The tiny chip that powers Montreal subway tickets
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It’s kind of the same, though. The physical communication layer is different, but the higher protocol layers are basically identical. Smart cards with contacts follow ISO 7816. These MIFARE contactless cards are ISO 14443 Type A cards, and their protocol follows ISO 7816-4.
This shouldn’t be terribly surprising — the entire ecosystem built for smart cards with contacts wants to support contactless cards with minimal changes, and this includes the host software, the readers, and the logic in the cards. There are even plenty of devices where the same device supports contact and contactless uses — plenty of credit cards, bank cards, and FIDO devices are like this.
This is analogous to WiFi and wired Ethernet. They’re have very different physical layers, but they are logically compatible, and the same software supports both.
MIFARE Ultralight does not actually implement 14443-4/7816/"smartcard"-style APDUs; it's significantly simpler, since the ICs are much less powerful.
To make things more confusing, some MIFARE ICs really do implement ISO 14443-4 (e.g. their fixed-function MIFARE DESfire cards, and their programmable smartcard ICs like SmartMX), but not all of them.
https://www.truecable.com/products/cat6a-field-term-plug-shi...
At that price point, there should be a wifi module hidden in it somewhere :)
[1]: https://blog.benjojo.co.uk/post/smart-sfp-linux-inside [2]: https://shop.hak5.org/products/omg-cable
One of the things you could do was pay certain types of widely used paper invoices. When I was brought on, the UI for this was just a standard HTML table with labels and input boxes. I decided to build a prototype with a paper invoice image as the background and a textboxes places where the numbers appearred on the paper invoice.
When people paid the invoice, they would have the paper version they had received by postal mail next to them. Now, their mission was to enter the numbers so they would end up with a visual one-to-one copy of the paper invoice on the computer screen. It made it easy for everyone to figure out which numbers to enter.
People embraced this immediately, and all forms were changed to follow this principle. All banks implemented it in their banking apps and still use it today.
They were designed to be machine-readable from the start for easy processing at the bank, and one of the ways they did this was by having all the fixed data encoded in a special font. When we started using smartphone banking apps, you'd just be able to scan a bill with your phone and it'd immediately read out all the data, fill in the missing stuff, and you'd only have to tap "confirm" to do the actual payment.
This is like a 100 bytes, a qr code can be over 2kb
This is a cheap plastic substrate with ink printing over the top. A qr code is just ink - or some other even cheaper printing process if you prefer.
This needs a specific ticket technology supplier over the next 10’s of years. QR codes can be drawn on screens or printed on paper and you can change suppliers for every component - from mobile phone apps to paper type to physical printer and reader devices - until your heart’s content over the next years. That flexibility can’t be underestimated in a space like public ticketing over decades.
Issuing replacement tickets needs physical presence to collect the ticket, vs qr code which can be emailed, sent on whatsapp, shared as a screenshot or photo if you need to, but of course you can still exchange physical paper qr codes if you prefer.
The rfid reader for these are cheap and durable, the optical reader for qr codes can be almost as cheap and almost as durable but not quite, the rfid wins this one point by a small margin.
I don't know about Montreal, but Moscow public transport uses similar paper tickets, also Mifare Ultralight, except you can get them for different number of trips. When you use your ticket, the turnstile or validator would increment those one-way counters so that the next one would know how many trips you have left. You can't do that with a QR code without either the reader or the user's device having a persistent internet connection to some sort of central server that would keep track of all tickets, which is impractical.
Slightly tangential, but when I was in Montreal, I was blown away that you just purchase a ticket from a machine and you get a printed out ticket with an NFC chip inside. Not my favourite part of the trip (Montreal is beautiful!) but definitely a cool piece of technology to see being put to such a mundane use.
The ticket vending machines print your monthly transit passes right onto the face of your card at the beginning of the month, and erase it after it expires.
It's not a QR code though. Just human readable text for bus drivers. (Turnstiles in the subway still read the pass via NFC.)
So the central server model is practical. The user's device has to have an internet connection at some point to activate the ticket within a reasonable period before using it but the connection doesn't have to persist after that. I don't know how their handheld scanners work in the Hudson River tunnels where there is no cell service but they do, so long as the user activates their ticket before the train departs.
Do you mean it would be hard for staff to scan cards? Here in the Netherlands both qr and cards (travel cards + bank cards) can be used at stations, and are read by the staff on the train.
So the solution is the transportation card is writable, and each train station acts like a small data center. They sync the data periodically to the main data center.
I think the syncing tech is getting better, Japan train companies are going to experiment with QR code soon. So read only is feasible.
That's also how the two subway systems I'm most familiar with do it here in Russia. In both Moscow and St Petersburg, the data stored on the refillable tickets (Troika and Podorozhnik respectively) was thoroughly reverse engineered. People who did it, of course, tried to write them too — for example, you'd make a dump, enter a station, then restore the dump with your old balance. It worked, but only for a day or two, after which the card number was added to a blacklist that all turnstiles check cards against. The conclusion was that there's a server on each station that turnstiles talk to, that syncs with some central server each night (when the subway is closed), where all system-wide transactions for the day are collated, and if anything is off, the card is blacklisted.
If they got filled up the the standard practice was free fares. :)
The bulk of the ticket will still be the Felica card though, because as far as I know neither the QR code or EMV open-loop system can handle required throughput of 60 persons/minute/gate.
To support the above, they did away with multi-trip tickets like you describe. It instead tracks and discounts once you hit a weekly limit (yes, you have to give up your privacy for this with an account or use your credit card directly). Not great for intermittent travel.
For systems like this the question is: if the internet is down and a few people get a free trip, does it really matter? You don't always need 100% accuracy if it makes everything else simpler, like removing paper tickets, printers, litter, etc.
The thing with plane and long-distance train tickets is that you buy them for a specific route. So all the checking only needs to be done at your departure station/airport, the code for which is encoded in the ticket, and the rest of the system doesn't need to know anything about it. But you can't do that with city transport. When there aren't multi-use tickets, people would often buy multiple single-use ones at a time and use them as the need arises, without knowing in advance when, where, and from where they'll be going.
Now this one time ticket needs to generated before entering the metro station and the qr code is scanned at * both entry and exit*.
I think the entire system works on daily rotating ticket id validated using unique hashes where a ticket validity period is tracked. I think this should be enough to ensure non-reuse of same ticket.
The caveat is, I have always only bough one time ticket which is the only mode allowed in qr. For daily traveller's, they need to buy token/card which is NFC based.
We actually have this for suburban trains, it's just a receipt with a 1D barcode on it. You use the barcode to open the turnstile (on some stations where they are installed), but otherwise the tickets are checked by controllers that occasionally go through trains.
For getting around a city though, I don't see much of a good use case. In my city, if you're here for at least several days, you're expected to buy the refillable card. If you're only here briefly and only need to use the metro a couple times, it's 1.5x more expensive but you'd buy tokens or tap with your bank card.
The ticket itself just has to encode an ID, and then the central database contains an entry for that ID that is checked by the gate in real time. When the ticket is scanned at a gate, the database gets updated.
And what about all those transfer discounts some cities have? Like if you're taking the subway and a bus within some timeframe, you still only pay once.
This is literally how all of the UK Mobile Train Tickets work. The ticket is a 2D barcode either on screen or on paper. Every gate / scanner operated by a guard records when the ticket has been scanned. They are synchronised and a ticket from being scanned twice. It's not that deep
Most cities you can use chengchema/dachema mini-apps in Wechat to generate the QR codes, but also all the old smartcards I had from previous trips worked in their various cities (but only work in that city) and usually had slightly cheaper fares than the QR-code ones, which were the same as the cash price to buy a single-use ticket.
But yeah, the bag checking is annoying in China. Shanghai is very relaxed compared to everywhere else - most places you even have to have your water bottle scanned to make sure it is actually water, or else take a sip from it.
Contactless ICs are more powerful in every other aspect: They're rewritable (allowing reusable tickets), they can support challenge-response authentication (allowing secure offline usage, which in turn makes for faster transactions at the gate), and they're much less finicky to scan in my experience.
I would have said that make it much more resilient, but I have seen so many buses that couldn't accept fares... I'm not so sure if it's the case.
The paper tickets can hold many fares, including unlimited evening fares or two day fares. I believe this would be hard to pull off with QR codes without having to keep track centrally.
If course duplication is probably a bigger risk for these tickets as they case be simply locked to one use server side.
But for subway/metro, during rush hour throughput it is important to able to tap an RFID almost instantly. QR is too slow and error-prone for subway/metro.
The world (including Montreal - these tickets are going away) has converged on credit card / phone / top-up charge card for that reason.
The problem with QR codes:
1. If they're printed, they can be copied.
2. "Dynamic" QR codes can be screenshot.
3. They're read-only (by definition)
4. Readers are slow, require good orientation by the user.
NFC is good because it's read/write, has a ~10cm range, the larger cards can hold up to 4K of data, the ultralights can replace single journey tickets and can be recycled like magnetics being captured at exit.
2. As per 1, no issue
3. That’d be a great feature if true, I’m all for immutability. However , qr codes can be defaced easily, hopefully the built in checksum defend against that. a more likely threat your system needs to defend against is that new qr codes can be generated extremely quickly
4. Both systems are the same speed, both systems require accurate targeting by the user, an rfid token slightly askew of the reader will not read since it won’t be able to influence / absorb the generated rf - most of these systems work by providing power to the rfid token and it communicates back not by transmitting its own signal but by exerting influence on the signal it’s receiving. It’s a very very low power interaction and very sensitive to positioning
A better problem than 4 is that you entail staff overheads with a visual system to keep them clean.
Read / write is a bad feature, you will lose ticket sales.
Recycling these is not practical. Direct reuse risks jamming the vending machine (used tickets end up subtly bent, very hard to reliably deal with), actual recycling isn’t viable, the energy required and emissions produced exceed that of creation of a new card from raw materials.
Yes, the question is not whether such system would be abused, but how much. But this is in the end what businesses care about.
Will QR codes be abused more than NFC chips? Likely yes.
Will it produce a larger financial loss than the cost of the NFC chips?
Can I mitigate these losses by a centralized validation system (each terminal needs a network connection with low latency guarantees)? Sure, but how much will it cost?
[1] https://www.facebook.com/uktvads/videos/kerching-a-saverstri...
On 4, QRs are substantially slower to be read and decoded. NFC/RFID have a range of ~100mm and the field shape is dependent on the antenna design, however it is way more tolerant than QR using IR/laser. As for "entail staff overheads", we are talking about systems that process thousands of taps/day through single gates. Anything that reduces maintenance requirements is absolutely a priority.
As for "read/write is a bad feature", I don't really understand your point.
Ultralite RFID/NFC tickets are routinely recycled where they are used to replace old magnetic systems that have belt transports for the magnetic tickets. The read/write heads of the magnetic stripe are replaced with NFC readers but the belt transport and capture mechanisms remain.
The huge disadvantage of NFC in this context is the electronic waste necessarily produced.
To bolster your point, aren't there whole countries where stores and street sales float on top of QR codes?
Actually, I think part of the reason is that so they know who's on the bus in case it's involved in an accident, because if you buy a ticket from a bus station for a "short distance" (so out of the city, but within about 40km), you also have to provide them with a phone number even though they never call you or send you an SMS using that number.
The CCP certainly do want to know who's on the bus, but not for the reasons you stated.
China's Big Tech companies taught Asia to pay by scanning QR codes, but made a mess along the way
https://www.theregister.com/2024/06/17/asia_qr_code_obsessio...
Transit has to work offline.
QRs are dramatically slower than NFC.
I still use a physical card - so that I have a backup option in case something happens to my phone - but even there the volume of waste is trivial. I've had my current transit card for ages, and it doesn't expire until 2037. It's possible that the only technological decision I've made that generated less e-waste was deciding to splurge on a mechanical watch instead of a quartz model.
Which is not something that you could do with a QR system. I don't know that anything is inherently wrong with QR codes, but they do seem to be a choice that's more appropriate for countries like China where the existing electronic payment infrastructure uses QR codes. In North America, by contrast, things have generally settled on NFC, and I think that that reason alone probably makes NFC the better option for North American transit systems.
I've got several apps that display QR codes on the screen for an external reader. One of them is for my health insurance id card (a simple 10 digit number), another shows my COVID vaccination status (this one is complicated, and I'm not sure why they used a QR code for it. It must include batch identification and other information given the size)
With a QR code like that, people still need to install an app, set up an account, etc. It's just a lot more friction. In cities where I can tap-to-pay, getting set up to ride a bus or train for the first time takes literally zero time; I'm already set up. If I need anything special - apps, accounts, system-specific QR codes, etc - then the setup time instantly goes up to a minimum of 10 minutes. It's a relatively large barrier to entry for infrequent riders, and ultimately serves to discourage use of public transit.
Exit gates usually capture the ticket on exit when it has been used up (ie single journeys, or after the number of trips encoded on the ticket).
These can (and are) recycled numerous times.
So if you're replacing an existing magnetic system, you can reuse the magnetic transports (belts/motors etc) for single use, including capture-at-exit and recycling for single journeys, while also adopting the NFC for multiple use.
The QR codes are significantly slower to read than NFC.
I've built both NFC and QR (and ye olde fashioned magnetic stripe) ticketing systems.
You make it sound like less moving parts are a bad thing :-)
I know what you're getting at though - the decentralized tolerance of network partitions and the ability to provide higher availability and faster decision speed at the entry barrier.
The system design constraints are hard but not impossible, my back of napkin maths says 5k/ticket scans per second with 99th percentile latency < 1000ms not only satisfies every use case that exists today but allows for 3x population growth beyond!
There's a few things in your favour when designing this system though. For example, in the case of network partition, you have geographic locality so a pen drive delivered a couple of times per day is likely feasible.
The system I recently put in allowed for that 450ms, the time broke down to:
1) NFC comms ~100ms
2) Network comms ~50-100ms
3) Physical relays (releasing barriers etc) 100-200ms
During peak periods the usual rate expected is 30-40 passengers through a gate/minute, which includes all of the time above, plus the passengers actually walking through the barriers (usually ~2m).
The barriers at rail stations have to have a defined maximum throughput of passengers, because it affects safety during emergencies etc. Most barriers are required to maintain somewhere between 30 and 45 passengers per minute.
Yes they can "default be open" and usually have emergency modes that disable validation entirely, but the speed during peak hour periods has to maintain the passenger flow.
However, for most transit, there is some form of "check in/out" (either through barriers/gates or via validation/inspection). This is combined with rules about "antipassback" (ie one user passing the token back to another to reuse), as well as "total time in system" (ie to avoid people staying in the system all day).
There are also rules that take into account entry/exit times (eg peak/off-peak), entry/exit locations (eg core/non-core zones) etc.
All of these rules require either:
a) An always online set of validators to be able to contact the backend that is maintaining the information, or,
b) a way to record the information on the token so that it is physically transported from one validation location to another.
It also is needed for inspection purposes during a trip.
If it was a short-lived QR code generated on your phone, then maybe. But the whole point of MIFARE Ultralight EV1 cards is that they can't be cloned. It's for repeated use, not for printing and using once.
A better application for QR codes is scenarios where it doesnt matter that its slower. Airline checkins, concert tickets, etc work well, a busy subway where people are queueing to get through a barrier as quickly as possible is one of the worst places to use it.
Separately we have revenue enforcement patrols with handheld scanners. The time from the red flash of the scanner on my screen (triggered by the person holding the scanner, it’s not constantly scanning) until the beep for ticket result is < 200ms, I.e. it feels very much almost instant but with a little perceptible delay.
Getting those QR code readers to read the QR code was a nightmare. Almost all the cameras have heavily scratched protective windows in front of them, which makes the reading process a struggle of trying to find a working angle. Of course the scratching is vandalism, but subway systems must be robust against vandalism, cause it's something that happens and must be expected.
I switched to per-transit payment via NFC after using one of the time-limited tickets and realizing that you need to consider yourself lucky if you find just one working QR code reader at most stations. NFC worked like a breeze.
Some of those downsides are positives (immutable, easily copied) others aren’t accurate, for example here’s the Mumbai metro in 2023 with qr entry gates https://youtube.com/shorts/TxbEgEzY9J8?si=s3gE-7_xbCbDoQ1d
Or that a 100% available central ledger is needed (it’s not).
That Qr code systems are in use today in some of the busiest locations would probably be the most succinct counterpoint though.
My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.
yup in mine plastic and metal but not paper.
Two common ways of getting around that is to either sandwich a plastic part containing the antenna to a metal one, or to punch out a circular part in the middle of the metal card and put the antenna in there (and close it all up using more plastic).
One card that doesn’t do either is the Apple Card – and as a result, you can’t tap it!
Well it's really annoying: the "metal" card (maybe as you say a mix of metal and plastic) is harder to swipe, so I got use to present it face down instead of face up, for I noticed that that way I get a better percentage of success on the first try.
I don't have the problem with my full plastic credit/debit cards.
Probably because it's around the size of a credit card and has fake smart card contacts printed on it. That being said, I would probably get confused myself too.
The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the instructions miss one step.
Following instructions is a good thing. Plenty of people damage stuff when putting it together since it looks obvious, but they usually miss critical details. I would imagine that the people who designed the card scanners had to put a lot of thought into their design simply because they know many people won't read instructions and would do as you suggest: figure out a way to insert [the card] somewhere.
Transit has different considerations though. It is critical that doing the right thing is obvious without reading instructions. Someone might have an important meeting to make and the time to read the instructions (or wait for the person in from of them to read the instructions) means they are late. Or (worse?!?) that time spent in line is annoying enough that someone decides to buy a car. You can somewhat get around this with more fare machines - but they are expensive and take up a lot of space. Fortunately we have human-machine interaction specialists who can tell you how to make a fare machine that is easy to use correctly without needing any instructions.
Thing I figured out assembling IKEA stuff in the past few years: if it seems like they skipped a step, look carefully at the details in pictures. Perhaps use a magnifying glass. There's going to be only one way to get from step N to step N+1, and all the information to figure it out is there. The drawings of all the pieces, from major parts to tiniest of screws, have accurate details, and there's enough of them to disambiguate the situation.
But why do people make incomplete manuals? If I have a step by step guidance and it doesn't work, because some steps were left out, than this is just a wrong manual!
(I share your frustration)
Ikea, on the other hand, prides itself on user experience. Everything is Ikea-branded, so any complaint will come back to Ikea because the buck stops there. Everything is sold internationally, and they don't want to translate it into a dozen languages, so they have to make clear assembly diagrams. Their entire brand is built around having great assembly instructions!
I mean, it's completely useless for people who has zero experience with camping -- exactly the people who need those instructions and videos and exactly the people who buy these types of tents from Costco.
Basically all other flat pack furniture I’ve ever bought has, but none of the dozen or so ikea items I’ve assembled. It’s part of why I only buy flat pack if it’s ikea, now.
One left out details in the diagrams in each step that they had deemed irrelevant to that step. This apparent attempt at simplifying the instructions stumped me for ages because I kept thinking I'd oriented pieces wrong due to the number of holes in the picture differing from the number of holes in the physical thing.
The other had switched some parts since the instructions were made, and hadn't bothered to update the instructions. This was a bit more obvious, but still kinda irritating for someone like me who is uncomfortable with uncertainty when I believe certainty should be attainable.
Whatever else can be said of IKEA, their manuals and quality control are excellent. I think of them as the McDonald's of furniture — it's never the best product, but it's damn good for the price, and you know exactly what you're going to get.
Trains in the UK still have a certain amount of "Which of these tickets/receipts go where?" while a line of irritated locals is building up behind you. Fortunately, also being the UK, someone will help you if you're struggling with something sooner rather than later.
£150 from London to Leeds?! I can fly halfway across Europe for less…
The unofficial BR Fares[1] website does a lot to untangle the complexity, although it can only do so much to mitigate the expense.
I used to work with someone who, even on an expense account, would roll their eyes if someone wanted them to do a last minute trip to London.
4-Day Interrail Global Pass, Adult passenger: €283
Eurostar seat reservation (any destination) x2: €060
= €340 (~£288)
This is Hacker News, but even still, I feel kind of icky suggesting a 500-kilometre detour to save money on a journey between two British cities no further than that distance from each other. How I wish we could just have a British version of the Austrian 'climate ticket' and leave all of our inscrutable rail fares behind us!
I guess it’s too bad I can’t save money on booking in advance, but on the other hand, I can easily jump on the train at any point of the day without sticker shock.
Some transit systems are just inherently more confusing than others. It doesn’t matter to the locals who know the quirks, but that doesn’t mean something can’t be improved. NYC has a great subway system, but I find the signage and general wayfinding quite lacking. Tokyo’s system is on a similar level of complexity but has excellent wayfinding and is generally much easier for a tourist to use.
In the end assholes designing it hid the payment terminal in such way that you can't see it from usual angle of use.. Amazingly hostile user design for those that rarely use that transport system...
The above assumes you know you will be there and so can look things up. I wasn't planning to leave the airport in one city so I didn't look up what locals do - then weather made me miss the connection and I was stuck in a city for a day.
Locals going to a new part of their own city often have the same problems trying to read the map and time tables. They are faster than tourists, but still need extra time because they don't know what is going on.
The logo you mention (four arcs actually) is owned by EMVco though, and they let people only use it for credit and debit card contactless payment cards.
There’s also an NFC logo, but as mentioned elsewhere, these cards aren’t really NFC cards, so that would also not be the right thing to use (I believe the NFC forum wants something to happen when you touch anything bearing that logo with your phone).
I used this knowledge to replace the QR code membership card to my friend's bar with an NFC card version, it looks really cool in your wallet compared to all the flimsy paper stamp cards from the other bars.
For vision-impaired people, NFC tags can be attached to objects and the phone can read an audio description when the object is tapped against phone.
Nowadays, I suppose most consumers do have RFID tags (debit cards, transport cards, building keys, e-Passports), they just might not be aware of the underlying technology.
This vendor has an array of RFID products: https://gototags.com
If you buy any standard NFC forum tag, chances are pretty good that it'll work with any Android or iOS device. The Ntag series has worked pretty well for me on both OSes and across various phones; I have one that instantly and cross-platform rickrolls everybody tapping it.
Where they make more sense is when they actually include dynamic information: Some of the newer tags can e.g. include an authentication tag in the URL part, which lets you verify the tag's authenticity (together with a web service that keeps track with the high watermark of opened sequence numbers).
I wouldn't call that "RFID" anymore, though; to me, RFID means transmitting only an identifier, with all the logic happening on the backend, but ISO 14443 tags get most interesting/useful when they go beyond that and do things like authentication or local processing.
What is the actual mechanism behind the DESFire and other secure NFC chips that prevents cloning?
The DESFire and other secure chips contain a cryptographic key that you can't access. Without the key, you can't make a clone of the chip. The cryptography provides authentication and encryption that you don't get with the cheap Ultralight chip.
I think this is all market segmentation; they don't put more security into the Ultralight chip because they don't want to cannibalize their higher-end sales.
Ultralight C does support actual cryptographic authentication.
Also, many of these transit systems are eventually consistent (they're usually offline-capable for resilience, but usually manage to send all validation transactions to a backoffice system within at most a day, and often minutes).
This allows detecting duplicate usage fairly quickly. In systems where you need to tap out as well as tap in to leave the turnstile, that's where ticket inspectors might take a sudden interest in you if you tap out with a cloned ticket.
In the end, as with most security systems, the goal is not to make fraud absolutely impossible, but to make it economically non-viable.
I can't think of a much worse way to do security. That feels like trying to flood the market with lockpicks that don't work instead of making a more pick-resistant lock.
There are single-use fares as well, the "CharlieTicket" that you might've encountered.
More CharlieCard NFC info:
https://medium.com/@bobbyrsec/operation-charlie-hacking-the-...
https://media.defcon.org/DEF%20CON%2031/DEF%20CON%2031%20pre...
I found myself in Paris having to cross the other day and forgot how terrible the old way of buying tickets was, amazed that it’s still the norm in so many cities
You can also store only an ID in a QR code, but you could also fit more information and a digital signature of it in there.
And sure, simply using the serial number might pose a security risk depending on the application, but that rarely stops implementors to implement such schemes. More often than not do people believe in security by obscurity, sigh. For a simply ticket system the serial number should be secure enought as it is a use-once application.
MIFARE Ultralight C and larger/more expensive chips allow challenge-response authentication, making them pratically uncloneable. These are usually used for reloadable and monthly passes.
How does this fit into the broader NFC ecosystem? What do other big metro systems like Omny, Clipper, Smartrip etc use? Apple and Google seem to implement some NFC protocols in their devices but in a much more programmable way, how does that work? Is the protocol used in credit cards related at all? And how do these relate to Felica, the system used everywhere in Japan (which was in the news for a while because the factory where they made the chips burned down and they had a chip shortage - giving Apple an opening to move into the market with iPhone NFC)?
As far as I can tell, the NFC ecosystem is a mess of competing, incompatible protocols from different companies, as well as incompatibilities for historical reasons. For example, Clipper uses MIFARE DESFire, which is the more secure sibling of the Ultralight chip that I examined. Washington's SmarTrip cards use MIFARE Plux X. New York City's OMNY, on the other hand, is apparently built on top of the Mastercard payment network using EMV. Montreal's rechargeable OPUS card (not the disposable one I examined) uses the completely different Calypso standard. FeliCa was developed in Japan along a different path and has a different standard (NFC-F vs NFC-A) with different modulation, protocol, and data rates. The NFC chips used in phones try to be compatible with as much as possible. These NFC systems all use the same 13.56 MHz frequency, so the radio hardware is compatible across them.
Theoretically Felica is a different stack from ISO 14443, but it's close enough that it almost got specified as a variant of ISO 14443 as well (C; MIFARE and most other systems use A). NFC does specify Felica as one possible official tag type (then called NFC-F, as opposed to NFC-A and NFC-B), so practically, most mobile devices can just also read it.
For anybody wanting to experiment a bit, I can highly recommend getting any Android device and installing NFC tag reader by NXP; it'll show you what technology exactly a given card uses, and in some cases can show you other interesting information as well. There's also an app that lets you read the current balance of various transit cards.
In e.g. London and the Netherlands, the readers were upgraded to support tapping in and out with a debit/credit card or Apple/Google Pay.
However, Apple also seems to have an ‘Express’ mode, which even works when the battery is empty (‘Power Reserve’).
It seems to me that there must be three protocols: the one for the disposable and stored-value tickets (ISO 14443?), EMV for debit/credit/Apple Pay/Google Pay, and Apple Pay Express.
Apple Pay Express is just Apple Pay without the need for the full system UI: "If iOS isn’t in use because iPhone needs to be charged, there may still be enough power in the battery to support Express Card transactions." it interacts the same way as the physical card equivalent (otherwise they would need a reader upgrade).
An AirTag can operate on a CR2032 for two years. An Energizer datasheet says that’s 235 mAh. An iPhone 13 Mini has a 2438 mAh battery (~10x). It makes sense the phone could do it for at least a day or two with the left over charge.
(I don’t know how long it would actually keep working)
EMV is an account-based payments protocol, and the card only confirms its presence in a transaction; balances are managed on the backend. The reader does not authenticate itself to the card at all.
MIFARE is a stored-value service and as such keeps track of the card's balance on-chip. This requires another smartcard on the reader side, holding the necessary keys for mutual authentication, but allows two-sided offline transactions, which is quite useful for transit applications (e.g. buses dropping out of network coverage, allowing higher volumes even during short server outages etc.)
MIFARE cards are used in all kinds of applications and not all of them require the reader to authenticate itself. And even in authenticated uses the keys don't neccessarily need to be stored in a smartcard (SAM) depending on the security requirements. For the simpler MIFARE cards a secure enclave for the keys doesn't even provide any additional security since they key is transmitted to the card anyway - and the simplest ones don't have any authentication at all.
I'd assume that the keys (more accurately passwords, since a key would never be transmitted to the card over an unencrypted interface) are diversified by card serial number though? In that case, it would still be useful to have an SAM to hold that diversification key. You could further store some MAC authentication tag on the password-protected tag that the SAM needs to see before revealing the password over the radio.
I'm not saying that this is how every transit system practically does use MIFARE Ultralight, but based on the design, it's definitely possible.
Google just has an Android API for it called HCE (Host Card Emulation), and anybody can write an app that implements it (i.e. Google Pay has no special position compared to competitors). In a nutshell, you just get a callback for every APDU (protocol message) the phone receives from the reader and get to respond as you wish.
Apple embeds a secure element in their devices, which is a chip almost identical to that you'll find in actual physical cards, but with an additional interface that connects it to the application processor, so that the OS and (privileged, i.e. Apple Wallet only) apps can interface with it and load new card applications. That's why the storage in Apple Wallet is limited to 50-ish cards, but Google Pay allows many more :)
Felica is not part of the ISO 14443 family, but closely related and also an official physical layer of NFC (NFC-F), so many devices practically support it as well. To my knowledge, there is no software-based emulation for it though (that's always a bit risky for stored-value cards), so Suica etc. only work on Japanese phone models that have the necessary secure element, as well as on all iPhones (Apple installs a Felica applet into their secure element on demand).
There are ways to mitigate that in software (e.g. by not ever loading long-lived keys into software, fetching them just in time after device attestation etc.), but while that works pretty well for the kind of payments where the terminal needs to be online anyway, it's very risky for offline transactions.
That's why Suica and most other stored-value passes only support iPhones and a handful of specific Android devices that have a secure element (or can use the SIM card as one).
Do you have any insight into the economics of this in general compared to other disposable solutions. Are manufacturing old school magnetic stripe tickets, or just optical scanning/barcodes a lot cheaper?
I imagine magnetic stripes have a higher failure to read rate at the turnstile causing issues, while both them and optical scanning requires the ticket to be inserted into the machine, adding complexity and moving parts.
The cool thing is that their thing doesn't work with all Android phones for an unknown reason (various people from the transit agency said "oh Android? Yeah it doesn't always work with Android"), which you have no way of knowing before topping up money and trying to use your phone.
If anyone is curious, it was a Xiaomi Redmi phone, a midrange one that has no issues paying over NFC. A OnePlus next to it with the same Android version worked just fine.
They've been trying to get contactless bank card payments going on the same turnstiles but roll-out has been bogged down by other transit agencies apparently.
Specifically, I use an AmScope ME300TZB-2L-10M microscope, which my friends consider an entry-level microscope, but it works for my needs.
I imagine those can use even simpler chips that are completely read-only over the air and only have a UID programmed.
[0] https://www.nxp.com/docs/en/data-sheet/MF0ICU1.pdf#G4008599
In the footnotes you said:
> One complication is that the counters have an "anti-tearing" feature for additional security
Two questions:
1. Why is it a "complication"? Is it just that it makes the counters more complicated, or is there something frustrating about the counters? 2. I would love to learn more about how the anti-tearing feature works!
A simple way of preventing tearing is to have two copies of each counter; if there is tearing, then the two values will be different.
Looking at an NXP patent [1], they use a much more complicated approach, using a level of indirection. They write the new value to a different memory page and then update a pointer to the new page. There are various progress bits recorded along the way so they can roll back as needed.
[1]: https://patents.google.com/patent/EP3226141A1
Here's an article describing an attack on the anti-tearing feature: https://blog.quarkslab.com/rfid-monotonic-counter-anti-teari...
Surely they're not using 75µm/120µm wafers throughout the entire production process - that's literally the thickness of a human hair! Can a 200/300mm wafer of that thickness even support itself, let alone all the stresses in the production process?
The problem is, they can be just as easily cloned. Your average Flipper Zero can do that.
If you want actual security, you have to go for a challenge-response scheme - i.e. every card is provisioned at the factory with a unique private / public key pair, and the public key gets signed by the factory. Then, to verify authenticity, the terminal gives some random nonce, the card signs it using its private key, and the terminal verifies that against the factory's public key.
> Even so, there were a couple of times that I lost track of the chip and had to check some specks under the microscope to determine which was the chip and which were dirt.
That is the really amazing part for me. We as humans have difficulty handling them, but how on earth does a machine even manufacture these, much less orient them consistently for the bond process to work?!
Not if the validation system uses the password feature of MIFARE Ultralight. For single-use tickets, which are invalidated immediately after being read, this can be good enough and is much more lightweight on the IC side.
Like what, there's Tiktoks advising young dumbasses precisely what they need to steal and joyride cars.
Yeah, because cars are valuable and joyriding a stolen car is impressive and cool to lots of teens. Getting a free ride on the bus is like negative street cred.
Another option is to just store used UIDs in a database. In fact, you could do a system with only UIDs. For a single use ticket, validate the UID signature and mark it as spent the first time it is used, then every use after that will be denied.
A card can be cloned, and it will work, once, it means one could steal a ticket by walking by and using appropriate equipment (not just a Flipper Zero as it is too short ranged) and use it before the legitimate owner does. I don't think it is something to worry about for a single use subway ticket.
To improve security for multi-use tickets, one could use rolling codes: every time a ticket is scanned and its UID validated, some code is read from the NFC memory and it has to match a sequence, the next code is then written back to memory and has to be provided next time, invalidating any clone. Tickets can still be stolen, but you can't beat the system unless you crack the server-side encryption.
More valuable tickets like commuter passes can use a different system with a challenge-response scheme.
Practical systems often are online these days, but only use that connection for eventual consistency style reconciliation.
> A card can be cloned, and it will work, once, it means one could steal a ticket by walking by and using appropriate equipment (not just a Flipper Zero as it is too short ranged) and use it before the legitimate owner does.
Even MIFARE Ultralight supports a basic password authentication scheme, where only legitimate readers know (or can derive) that password, so there a bit better protected against cloning than pure passive storage cards.
Sure you just have to accept that you're now vulnerable to Denial of Service attacks, or just DoS due to unrelated service infrastructure outages caused by things like backhoes.
> much less orient them consistently for the bond process to work?!
It's not all that consistent. They have a 3% failure rate. And you have to accept a unique map of "broken chips" with every single order you receive.
But you can only clone a ticket who's ID you use. So you can buy a ticket and clone it, but what have you achieved? It is still validated "on the backend" once you use either the first time.
So the only real risk is that you clone a random person's ticket between them buying it and using it which is a security flaw, but probably a very minor issue in real-world use.
Maybe there could be slight issue with day passes? You could buy a single day pass then issue clones at a lower price. However it is likely not an issue worth paying for more expensive chips to avoid.
My understanding is that they are one time use?
In New Delhi metro, India, they used to use plastic tokens with these chips, but at the end of the journey, to exit the station you have to give the chip back.
Nowadays, they use a printed QR system, and they have even gone paperless. I can buy the ticket with my mobile app, pay using UPI instant payment, and show the qr code on the phone to the scanner and then travel.
For monthly card holders, rfid chip based cards are issued.
Lifetime of a plastic opus card may even be more wasteful, by mass of plastic and chip, if not used extensively. For example, one time use is often for tourists, where a full chip opus would be very wasteful indeed.
That's just whataboutism: If there's an alternative way of solving the same problem that generates less waste, why not use it?
I find the contactless coin form factor for single rides quite clever personally, and I don't see any downsides compared to paper single-use tickets (other than that validators and gates need some storage container to collect them, which could be tricky in buses).
Airline is not just whataboutism. It illustrates the absurdity of scale in your point. Imagine someone who is spending 20 minutes to save themselves 4 pennies on their electrical bill, but they are running 8 air conditioners with their windows open during a heatwave. Yes, that's whataboutism, but it's an informal fallacy, meaning I may still have a good point.
The antenna isn't, however. In any case, I think there's a pretty high chance these tickets will not end up in a dedicated recycling facility that can properly separate antenna from paper and recycle both, disregarding the chip.
For similar reasons, Japan is phasing out even magnetic stripe single-ride tickets out of recycling concerns (in favor of QR code based ones).
> Imagine someone who is spending 20 minutes to save themselves 4 pennies on their electrical bill
That's not an appropriate comparison, though. Buying a reusable token doesn't take 20 minutes more than buying a paper ticket.
Imagine instead a device manufacturer spending some months of R&D to help every single household in a large country save 4 pennies on their electrical bills, and it doesn't seem so absurd anymore.
No, but it could expend 20x the resources, and not be used 20x as much.
As the article mentions, the purpose of these paper tickets is for single-use or short term use, and the system also supports plastic cards for longer term use.
I couldn't find any data on usage for one vs. the other, hopefully it's not a crazy amount. I'd imagine that most people who use transit on a regular basis do not use single-use tickets.
In the app that is used by me, the brightness of the screen is automatically increased by the app as soon as I open the ticket QR, and then reduces to its previous state, once the QR code display is removed.
Contactless tickets work both ways, and in addition to that usually have a larger, more forgiving "landing area". On top of that, they can usually read through a wallet (but that's more relevant to regular commuters, arguably; tourists and infrequent riders will likely have purchased the ticket just moments before using it).
However oyster really is in its way out for most uses. contactless and especially a phone is far more convenient for non season use, and far less wasteful.
https://tfl.gov.uk/fares/free-and-discounted-travel/national...
I'm looking forward to not having to choose one trade-off over the other.
It’s still fast enough that it will read my Apple Watch before the gate starts to close from the passenger in front of me.
One saved trip to an Oyster top-up machine will make up for a lifetime of contactless NFC latency!
The Japanese transit cards that are supported by Apple Pay have that option, and it's arguably the best of both worlds.
It is, there’s even an auto top-up option that adds credit automatically if your balance drops below a certain level.
But there’s no “digital” Oyster card, only physical ones. If you want to use a device to pay you have to use contactless.
And either way, it’s still kind of a pain to have to maintain a balance - especially if you’re a tourist or visitor and don’t know exactly how much credit you’re going to need.
I agree that being able to load a transit card into Apple Pay etc is also a good solution. The convenience of not having a physical card that can be easily lost or forgotten is probably the biggest benefit for me.
Octopus (used in Hong Kong) is the one that supports virtual cards in Apple Wallet.
In Japan credit card transactions routinely take a couple seconds. Imagine each person taking 5 seconds to go through the gate! I think what trials for credit card payments in transportation services there are doing is simply not processing the transaction inline, and just doing it after the fact (assuming it will go through).
If you try to use a card that is valid but has no available balance/credit, it might work for the first ride but then be blocked when you try to use it for the return trip.
Fares are batched throughout the day and you are charged once, overnight, for all rides that day (after applying any multi-ride discounts, etc).
This is different from some other cities where I’ve used contactless payments and they’d charge you immediately for each ride, giving you lots of annoying little charges on your bank statement!
Don't ask me how though
Wrong. With the traffic volumes normally seen in Tokyo, those few hundred extra milliseconds will cause huge delays at the fare gates. There's a reason the systems here use the Felica card which processes in 100ms: it's really needed for this kind of pedestrian volume.
https://support.apple.com/en-us/118625
You don't have to unlock your phone -- just tap. If you have an Apple watch, just put your wrist to the reader.
I use this all the time in NYC and it's so fast.
Here's a good summary of NFC protocols used for transit gates: https://atadistance.net/2020/06/13/transit-gate-evolution-wh...
The Felica standard is fastest at 100ms per tap, and is used in Japan (e.g. Suica card) and Hong Kong (Octopus card).
It's conceptually very similar to MIFARE – a fixed function IC implementing a fully offline stored value purse – but uses a stack that differs from ISO 14443 A on pretty much all layers. (It was planned to possibly become ISO 14443 C, but that never happened.)
Yes: Felica was developed by Sony in Japan, but was actually first adopted in Hong Kong, then later in Japan. It's far better than other standards, because it's so fast.
The only ones that I came across that are not Mifare, and not even readable by Android (but readable by the Flipper Zero), are the paper tickets used in Brussels. Then, of course, there are non-NFC tickets. For example those that use magnetic stripes, like the cute tiny ones in Paris or NYC's MetroCard.
There are two distinct types of Oyster card, but I don't know which is which, other than from a user perspective. All I know is that I had an old style one (the one without the white D in a blue square on the back) and you could still use it, you just couldn't "connect it" to the app so you couldn't look up your travel history.
There was a complicated process for returning it and getting a replacement, but as they'd already phased in paying by bank card by then, and the only advantage of an oyster card was for season tickets, I just returned it and got my deposit back.
But if you're into collecting different card types, you might want to try to get hold of one of these old ones as well. They're probably somewhat rare now, as they were encouraging people to upgrade to the new ones at least 5 years ago.
Also, you see these Montreal cards laying all over the streets. This card system just seems so messed up in Montreal.
Back around 2010 I remember reading these accusations that significant part of revenue went directly to Mifare for the massive number of chips.
And for single rides, some of Metro systems still use these steampunk brass tokens. Sometimes, less authentic plastic.
and every transportation system that pretends to run as a profit center and not a cost center also makes ton of money for the vendors.
Too many times I have been stuck in 15-20 minutes queues to buy those tickets and you cant refill them with an app... Plus south shore and north shore have they own system it's a mess.
There’s the OMNY card, and I believe the original plan was to outsource sales and top-ups to third-party stores, but lately I’ve also seen some vending machines for that in some stations, so maybe they’re going back a bit on that idea.
In the old days you’d nominate a specific station, and the credit would be transferred to the card the next time you tapped in at that station.
But now days I don’t think you need to do that: presumably it maintains the balance primarily on the server side now rather than on card.
I remember using that feature in the SF bay area, and while it took a day for the top-up to actually propagate to all readers, it even worked on buses, so they must be uploading that data everywhere.
That type of connection needs to be there in any system that supports lost/stolen card value recovery, in any case, since that's how card block lists are distributed.
But yes, for speed/redundancy they are still probably using the stored value balance too.
TfL likely need that mechanism primarily to synchronize the list of blocked open-loop bank cards with unpaid balances to all readers. Faster Oyster transaction list updates and any-station remote top-ups are probably just a side effect of that.
Clipper doesn't (yet) support open-loop bank cards yet, so for them, it's probably enough to update more remote readers every time the bus goes back to the depot, for example.
- Full offline support (i.e. both the reader and payment device don't need network connectivity), making the system more resilient
- Symmetric cryptography and highly optimized transaction flow, making reads more reliable and allowing faster customer flows through transit gates
- Upfront transparency about charges, monthly passes, capping etc. – you immediately see your balance left after tapping.
- No "transaction spam". This is more on my specific transit provider (NYC MTA), but I'm really not a fan of getting an individual credit card charge for every. single. tap. It can't be cheap in terms of fees for the operator either! At least other systems, like TfL in London, aggregate taps over a day, but it's still not great.
Singapore's public transit agency recently attempted to switch from a stored value based model to an exclusively account based one, but had to backpedal quickly due to public outrage about the move.
Ideally, a system supports both payment methods: Open-loop payment cards for infrequent users, and stored-value cards (both physical and in digital wallets) for heavy users and anybody else that prefers them. But realistically, maintaining both is too much of a burden for many transit agencies.
I would argue that contactless debit/credit card or mobile wallet taps are substantially more convenient for tourists and occasional users – if you are fresh off the boat (or off the plane – for a more modern twist), not much can beat the convenience of turning up at the turnstile, tapping on and getting on with the trip on the local public transport network and tapping off at the end of the trip.
No need to look for a place that sells local rechargeable or disposable NFC cards, having to be aware of a low balance, looking for a place where the card can be topped up, actually top them up and stuff like that. For frequent travellers, it also entails having fewer non-portable mass transit payment cards to carry.
Bonus points: debit/credit card/mobile wallet payments also eliminate the problem of the discovery and consolidation of lost balances when a card gets lost, and it reduces the environment impact (manufacturing + energy consumed during the process) and the wastage (the disposal or, rather, the lack thereof) that disposable NFC cards inherently possess.
That is what Sydney (the one that is not in Canada) has done: they went straight from prepaid paper tickets to their own rechargeable Octopus/Oyster style cards (with the name also beginning with an «O» – Opal) followed by enabling debit/credit card (Visa/MC/AmEx) and mobile wallet NFC payments later within the larger metropolitan area public transport network on buses, ferries, trains and trams.
Convenience, as always and of course, comes at the expense of privacy, though.
I suppose it is a matter of personal or circumstantial preferences so I won't go into that, but through reading this discussion, I have learned that, e.g. the Boston MTBA's CharlieCard, have an expiry date and has to be replaced in person. From the regular commuter's point of view it is a nuisance of epic proportions – to turn up at a bus stop or a station only to find out they are unable to pay because their dedicated card has expired. The commuter is only interested in the act of paying the fare and not in complexities of the local mass transit system's payment network shenanigans.
I also can't help noticing that the wallet (the purse style) making business has taken a hit in recent years due to the rapidly decreasing circulation of cash and the rise of mobile wallets. Many people now leave their homes with their smartphones and keys only. Eventually and inevitably, all cities will embrace either the integration with or adoption of mobile wallets, but that will take a while depending on how well each government funds its local public transport agency.
Apple Wallet supports transit cards for dozens of transit systems, and most of them have some associated app to allow managing monthly passes or topping up the balance. Arguably, that's the best of both worlds.
Apple Wallet supports neither the Montreal (the subject of this discussion) nor Boston CharlieCard transit cards nor many more. Apple Wallet has promptly shown some transit cards from mainland China, 1x from France, 1x from Hong Kong, 3x from Japan and only 3x (!) from the US (Clipper, SmarTrip and TAP). That is all it supports. Android may support more.
The said CharlieCard[0] supports a bespoke mTicket app that is neither integrated with the mobile wallet nor fully supports all modes of transportation in Boston:
√ Best for Commuter Rail and ferry riders who don’t often take the subway or bus
∅ No transfers to other modes
And, since the onus is also on the government to upgrade NFC readers across the entire network anyway – to support modern ways of paying, the question is which one is more future proof: 1) natively supporting a local transit card at the smartphone level + upgrade the NFC readers to support a variety of NFC protocols, or 2) upgrade the NFC readers to support the debit/credit card and mobile wallet payments only? I am inclined to think that (2) is more efficient and more cost-effective for taxpayers.
But practically, a lot of them are run by a small set of contractors anyway, not any government entity directly. These only need to integrate with wallet providers once; beyond that it's just a matter of contract terms and uploading a few new assets to Apple's and Google's servers. (I believe Apple can even launch new transit cards without an iOS update these days.)
You can now refill the rechargeable OPUS cards using an app.
- Montreals subway stations have this gritty, distinctively french atmosphere i loved it.
- Vancouvers above/below stations have no soul, distinctively anglo but above ground ones i liked.
- Montreal train cars use rubber wheels to my shock! Extremely loud.
- Vancouver train cars use some sort of electric system which im not familiar with ( have a few variants (newer hyundai rotem cars, old ones: https://www.youtube.com/watch?v=W_BoeXqaV9c)
- Montreal subway does not cover the entire region like Vancouver's skytrain. Getting around is difficult without uber. Road conditions are horrible (pot holes remain unfixed for decades, city went broke hosting olympics long time ago), I just shudder how you can get around during the winter.
But the biggest shock was that in some instances, it was faster for me to walk then walk to the station and wait for the subway.
- Arriving at YVR: Skytrain runs directly from airport to a satellite city where its numerous public buses cover almost the entire MV. I could just tap through the toll gate with my credit card and wait for a bus which arrives on time quite frequently.
- Arrriving at YUL: Have to take a bus from airport for 30 minutes to Montreal but doesn't seem to respect time schedule. Got off somewhere in Montreal I don't remember (there was a large open artsy area) tried to wait for a bus but never came, gave up, got uber.
It's not supposed to. The new REM train network (a few stations already in use) will cover the region. By 2027. Maybe.
REM will also go to YUL.
PS. Fun fact, REM is also driver-less just like the Skytrain.
Meaning that if you just buy the normal ticket in any Montreal station and make the mistake of going to Laval, you can be fined and they do tons of ticket traps because they know that people make that mistake pretty ogten. It's not even a separate line or something. And the same card wouldn't let you take a bus in Laval because again, it's another ticket (but not the same as the one for the dual zone metro that I was talking about earlier...). Just a huge mess when it used to be much simpler before they "streamlined" it.
The Skytrain to YVR is indeed very nice - built for the winter Olympics. Maybe not as "connected" as some European airports but quite convenient.
The problem with transit in Vancouver is that most of it is rays emanating from downtown, i.e. you have fairly decent (though IMO worse than most large European cities) transit if you need to get downtown but it's terrible useless if you need to get across. My work used to be 20 minutes drive time, >2 hours transit time.
Skytrain doesn't exactly cover the entire region, as you get further away from the downtown core the coverage gets much spottier until when you get far enough (but still part of metro Vancouver) it's non-existent.
There are certainly times when buses don't show up on time. I take transit these days to work and back and I would say something like 30% of the time the bus isn't on time. About 5% of the time the bus I'm supposed to take just never shows up.
i'm from vancouver, and every day I take the NYC subway i wish it was cleaner and more soulless, more hospital sterility, harsh 6500K lighting, glass and stainless, and less literal grit
These exist, but they're all behind NDAs and you're not allowed to have them. They're used for e.g. EMV.
I think it's a M24LR04E.
Costs like $0.50.
I think these could be useful for devices where you have a limited amount of data you want to read or transfer. Like why have bluetooth and all the crap that entails when all you want to do is configure a device once.
Advantage of a separate IC is you can use it with whatever microcontroller development stack you have working.
More generally what I'm seeking is something in the card form factor which is suitable to store cryptographic secrets (i.e., a smartcard).
Separate IC is a disadvantage here since it creates a vulnerable security boundary and makes it infeasible to integrate the chip into a thin card.
Worth bearing in mind that in the UK train stations have mixed NFC, QR and magnetic readers. The ones which are the least reliable are the magnetic readers which operate on paper cards. The NFC readers are used for pre-paid ticket cards and credit/debit cards. The QR scanners for so called "E-Tickets".
I don't really ever see anyone have problems with the QR tickets (they're static and distributed as PDF or pkpass). Likewise with NFC. Only the paper magstripe cards commonly cause problems.
Meanwhile in the Shanghai metro they use chip coins. Small, reusable and NFC.
I think these paper NFC things are a unique combination of non-reusable, prone to damage, prone to jamming.
But they are cool.
That still seems expensive for a $3.75 metro fare.
2.4% of the cost of your ride is the chip in the ticket itself? Maybe it's worth it because it lets them eliminate mechanical ticket-reading and unify paper tickets with other NFC payment methods.
The vast majority of users will use rechargeable Opus cards [1] that can contain a variety of different fare types (single tickets, monthly tickets, etc).
From an operator's point of view it definitely makes sense to only have to maintain one type of reader, even if that means losing a few cents profit on the low single digit percent of rides that use the disposable tickets.
[1] https://www.stm.info/en/info/fares/opus-cards-and-other-fare...
Ha ha ha ha... Love it! Always informative and interesting :)
As for the comments, there seems to be a big discussion on whether NFC or barcodes (includes QR codes) are the better technology for public transport ticket I have a completely different view: No matter what technology you are using, after having used public transport in multiple cities in Germany with the same flat rate tickets, I wonder if this could be feasible in every city or country. Just not caring about a ticket seems to be the most user friendly option. It seems to work well, but such a system would need to prove itself in areas where public transport is already quite crowded, like London.
"This is a genuine, serious proposal. Cars and car infrastructure are so enormously expensive and destructive. Paying people to use public transit instead would be a net positive, and it's not even close."
From: https://hachyderm.io/@jenniferplusplus/112667806776752372
Getting set up to use public transit as a visitor to a top tier city like New York, Brussels or Montreal (I can't speak to London) is easy. Usually they have explanatory signage and staffed kiosks at all the major intercity transit stations. And good websites that clearly explain what visitors need to know to navigate the system.
It's visiting a city with a lower-tier transit system that tends to pose a greater challenge. I'm thinking here of cities like St. Louis, Milwaukee or Portland. Stations may not have attendants, automated kiosks may not be well-maintained, websites tend to be ill-designed or be missing key information about how to use the system, etc. And, on top of all that, I'm not necessarily visiting there often enough to amortize the (already relatively high, due to the aforementioned problems) cost of getting to know the system across may visits. And I certainly don't want to have 15 different transit apps and payment accounts to juggle. Standardizing the fare structures and payment systems could be a big boon to visitors.
There's potentially more value to the the smaller transit systems themselves in standardizing, too. None of them is individually a large enough system to achieve good economies of scale w/r/t the technical and administrative costs of maintaining their own special snowflake fare system.
If you want a concrete american privately run and open to the public example, see Stanford's buses in Palo Alto...
We’re now down in the single digits for fabrication in nanometers, although I know that sort of just a name. This chip is so tiny already, if you were to fab it on a process like 7 nm I’m guessing it would be unworkably small. Too hard to cut, too hard to manipulate individual chips once you did manage to cut them.
So here’s my question: how small can we make a chip in area while still being able to cut them out and easily use them?
It’s obviously not a concern for the hundreds of square millimeters of a large processor, but I’ve never heard about the opposite end of the spectrum before.
Looking at a random die pick-and-place machine [1], it handles dies down to 0.2mm in either dimension. So you could handle smaller dies than mine with an off-the-shelf machine, but not a lot smaller.
[1] The video of the die machine in action is pretty cool: https://www.syagrussystems.com/dts-2-die-sorter
The increased losses due to cutting make sense too. I was expecting the cuts to be wider than 20 µm, so that’s not actually as bad as I was imagining.
Unfortunately, most things I could find are in Japanese, as expected; I suspect that the really interesting parts aren't public, as usual in this industry (there's still a lot of belief in security by obscurity, even if the systems actually don't need it).
Singapore's CEPAS seems very similar conceptually to Felica (at least in application, in that there's multiple issuers of stored-value cards with interoperability), and the specifications for that seem to be available for purchase, but I'm not curious enough to bite that bullet yet :)
The author understands Japanese sources and writes about how the various Felica-based systems operate and evolve.
One small caveat: As much as I appreciate his writing, I'd take some of the technical explanations with a grain of salt – the approach is definitely more that of an (extremely knowledgeable and experienced!) outsider looking at the system and coming up with hypotheses for its workings than that of an authoritative source with hands-on experience working on the system. It's sometimes not that easy to figure out what's hypothesis and what's "confirmed" knowledge as a result.
That said, much of what I've learned about Japanese transit payment systems (without ever having visited) was via that blog. It's amazing!
Somebody from the tiny intersection of people apparently having hands-on experience with Felica and writing about it in English is this pseudonymous Reddit user (often also quoted on the blog): https://www.reddit.com/user/FelicaDude/
An NFC card doesn't actively transmit data. Instead, it sends data using "load modulation", where it switches a load across the antenna to change how much power it absorbs. The transmitter can detect this change in power, but the signal is extremely weak (80 decibels below the transmitted signal), so it's amazing that it works at all.
This does mean that iPhones can't do cool tricks like booting up the secure element purely from the field with a completely dead battery though that some earlier Android and Windows Phones could do (or at least Apple has intentionally deactivated that capability for a more consistent/secure experience) :)
Powering up the IC actually doesn't take long, but the processing itself can: Contactless payment transactions (mostly) use asymmetric cryptography, and old one at that too (usually RSA), so simply crunching the numbers takes these fairly underpowered ICs quite some time, even when they include cryptographic coprocessors.
Compare that with (symmetric key based) transit ticket authentication, e.g. for MIFARE DESfire or Japanese Felica cards: These usually use DES or AES, which is lightning fast in comparison.
If you don't want to use disposable ones, the same kiosk that dispenses the temporary cards will allow you to buy a permanent one which you can load with fares as normal.
Most people in Japan actually use (reloadable) IC cards, as far as I understand, and railways seem to be in progress of switching magnetic stripe tickets for QR code based ones: https://english.kyodonews.net/news/2024/05/362243d2c187-japa...
Neat stuff, though I can’t say I love the concept of e-waste NFC.
Part of the “software eating the world” story is the decreased cost of precision that enabled the hardware substrate of software to be inexpensively and ubiquitously included in any mass produced object.
IC fabrication produces a lot of chemical waste, and I would imagine that these ICs aren't fabbed in a place that has a great track record on pollution.
I'm not saying there is none, just trying get an idea of how much of a problem this really is. We also need to consider what impact any alternative solution would have.
What struck me from the description of the system was that it seems that no electronics is really needed at all, a unique QR or barcode would be just as good because the back end system records the use.
But that would require the installation of optical readers in a system that might not have them but does already have NFC readers. Adding those readers would add a considerable amount of e-waste too.
The other factor is that people who use tickets regularly would use the rechargeable plastic cards, rather than the disposable tickets, so the amount of waste is reduced.
Many transit agencies do explicitly incentivize reuse, e.g. by offering cheaper fares using a reloadable contactless card and often charging a deposit for that card.
Even then, many of these systems have been struggling due to the IC shortage, given the low margins these single-use tickets have to operate on. In some Asian countries, including Japan and Malaysia, it was tricky to get a new transit card for several months or even years, even though there is a deposit charge.
It does add significant costs to the transport system. Single-use NFC cards must cost at least a few cents to produce and dispense, which adds up when you’re talking about hundreds of thousands or millions of rides every day.
Even reusable NFC cards are costly in terms of providing all the infrastructure to support them: software, servers, enough top-up machines in stations to handle peak demand, commissions to retailers selling the cards, extra staff to deal with customer support, delays and congestion caused by top-up/ticketing queues, etc.
That’s one reason London’s TfL has been pushing everyone to just use their bank-issued contactless credit/debit cards (or NFC-enabled phones) for years now.
It’s also more convenient, of course, to never have to worry about your balance or recharging the card.
Unfortunately the days where you could ride the buses for free around the whole Heathrow area are gone, however.
A ticket needs to be printed anyways, the single use ticket with chip does not come from thin air.
The NFC doesn't need to be printed. It just needs to be dispensed.
My city went from printed paper tickets, that didn't even need to be scanned, to contactless fare system with paper NFC tickets. It saves money having simpler and less used ticket machines. It helps that most people use contactless credit card or fare card. They really should have more signs that can tap phone or credit card cause I suspect tourists think they need to buy ticket.
Magstripes tend to work not so well when you have the ticket in your pocket for a couple days, printed codes involve people futzing with cameras. You can use a sort of card ingestion system to line up a QR code or the like... but those things are complicated and break down a lot! You end up needing staff to constantly be opening it and unclogging it. This works alright if you have like 6 turnstiles, less so when you have 2 or 3.
Obviously you can work with those models anyways, and plenty of transportation networks do! But if your rush hour involves moving a million+ people, you really do need this stuff to go fast.
How very true... SWIPE CARD AGAIN AT THIS TURNSTILE in glowing turqouise-ish dot matrix letters will be forever etched into my brain long after the Metrocard is finally gone.
Personally I collect the cards instead because I have a tendency to revisit cities years into the future. I just wish cities wouldn't make their cards expire so damn quickly. Wuhan's metro is nice, the cards don't expire until 10 years later. But I've found Singapore and Taipei expire within 3 years and you lose your stored money.
I have this "brick" of public transit cards for about 20 cities. It feels powerful. I kind of wish I could just swipe this brick in any city and just go. Unfortunately they all interfere with each other.
Just let me pay with coins, or a credit card in seconds, with no return work.
My guess is this might be because on-the-fly credit card authorizations still take too long. Waiting 3 seconds for an EMV contactless verification would seriously hold up the line at rush hour in a country where most people live by public transit.
If I were to guess, the registration is probably what enables them to pre-authorize a credit line and allow you to tap in in a fraction of a second.
I have no issue with temp cards, if I can buy them right at the pickup location. I once flew into a place late at night, and only stores had cards to buy, and all were closed.
Duh.
The vending machines at every station should be capable of directly vending public transit cards. I think most of the better systems around the world do work that way.
London has been using contactless for a while.
Are you sure that's true? Their website says otherwise:
> Do I need to sign up for a SimplyGo account to use my contactless bank card for transit? You do not need to sign up for a SimplyGo account to use your contactless bank card for transit.
Did this change recently? I travelled a little over a year ago and my Wise card worked right after I landed at the Singapore airport.
I’d bet a lot of them are sold at the airport: the fare to downtown comes with a 24-hr pass for other buses and metros.
Ticket in english sometimes refers to a season or monthly ticket, so it’s pretty ambiguous.
Some people live on a different continents and their environment looks completely different. This is giving me same vibes as those ‘probe you are not a robot’ tests that ask you to identify things that are specific to USA’
In Portugal, you pay extra for the initial ticket, but subsequent uses are cheaper, because you are using the same physical ticket.
Pet peeve: Calling these chips "NFC" is a bit misleading. NFC-A isn't defined by ISO 14443-A, but builds on it.
NFC is an umbrella standard that defines a way of storing structured data on a wide variety of existing contactless IC technologies (including, but not limited to ISO 14443) and products (such as NXP's various MIFARE chips, which in turn are based on various layers of ISO 14443 up to -4).
For the concrete example, it's correct to say that one possible implementation of an NFC-A tag is MIFARE Ultralight (that would be a NFC forum type 2 tag), but neither is NFC the only thing you can do with MIFARE Ultralight (and this transit use case almost certainly doesn't put an NDEF container on the ticket), nor is this the only type of tag you could use for NFC.
Yeah, then it's appropriate to call this NFC.
Importantly, NFC standardizes a way of storing structured data like URLs or phone numbers on NFC tags; transit tickets most likely don't use tags in that way.
The reusable OPUS transit card expires after 4 years unless you have a photo registered. In almost all cities, adult transit cards don't expire and don't require photo/name registration. https://www.stm.info/en/info/fares/opus-cards-and-other-fare...
The system does not have a concept of a monetary balance ($). The system only has tickets (bought in blocks of 1, 2, or 10 with appropriate discounts) and unlimited passes (24 hr, 3 day, week, month). Note that I define a "ticket" as an abstract authorization to ride transit for one trip, not a physical object.
There is no discount for using OPUS. If you buy a block of 10 tickets, it's the same cost whether you load it onto a disposable paper card or on a plastic long-term OPUS card. There is no incentive to reduce waste.
The Greater Montreal Area is divided into fare zones, A/B/C/D. You can use any supported transport agency and vehicle (bus, subway, commuter rail, possibly others) to make your trip. Ticket/pass types have cumulative fare zones, i.e. A or AB or ABC or ABCD. This isn't wrong per se; this is just setting up a definition for what's to come.
An OPUS card is locked to one set of fare zones for the purpose of buying tickets. For example, your card might be set to zone A, or maybe zones ABC. You can only buy and spend tickets of that type. However, you can buy passes for any zones, but they are expensive and intended for long-term commuters.
A new paper card can be bought for any set of zones. e.g. If you want to travel from somewhere in zone A to somewhere in zone C, you buy a zone ABC fare ticket. A paper card cannot be reloaded after the initial purchase.
There is only tap-on, no tap-off. So if you board at zone A, there is no way for the transport system to electronically know if you exited in zone A, B, C, or D. This also means that an open payment supporting credit cards cannot deduct the correct fare amount. There are random fare inspections from human officers to ensure you hold a tapped card with the correct fare type at the location of the inspection.
In light of this entire setup, I can understand why an OPUS card is locked to one set of zones for tickets (which are counted down as you use them). If you tap your OPUS card at a reader in zone A but you own tickets of multiple zone types on the card, how does the reader know which ticket to deduct? Montreal has brought this problem on themselves by not having tap-off and also not using a money-based system.
To make matters worse, the fare vending machines at subway stations are inadequate. There are not enough of them, the menus are slow to navigate through, paying by cash or credit card may have additional frictions (e.g. cash rejected, no change, card payment failure). Thus there is often a queue to buy tickets, making the travel experience that much worse. (Meanwhile, I found Japan's ticket-vending machines to be top-notch - very clear instructions, fast machine response times, and excellent handling of cash.)
By comparison, Toronto has a different strategy and different problems on the PRESTO contactless fare card. The TTC has a flat fare and 2-hour free transfers within the system. GO transit has tap-on and tap-off for buses and trains. For a long time, there was no fare integration between transit agencies, so you had to pay separately on each system; this changed in Feb 2024 so that you pay more or less the maximum of what each agency on your trip charges rather than the sum of the components.
Japan's transit systems mostly use tap-on tap-off, even many buses, and charge by distance. (There are small exceptions like the Kyoto bus being flat fare.) Transit pricing and ticketing is almost an entirely solved problem for decades; the rest of the world can learn from them. (There are still small exceptions, like how travelling between two different IC card regions, like from Numazu to Tokyo, requires a paper ticket.)
As you can see, even if you live permanently in Montreal and own an OPUS card (e.g. zones AB), as soon as you need to make a trip outside (e.g. zones ABCD) your usual area, you need to interact with a ticket-vending machine and buy a paper card. Meanwhile, in Toronto or Japan, you hold one card and the transit systems deduct the correct amount of money based on the trip that you take. Heck, Toronto introduced open payments in 2023, so you don't even need to buy the transit card.
Again, this problem wouldn't exist if we can optimize WFH methods. We don't need to solving "physical problems" from start to finish. Making, distributing, and recycling all those ticket papers.
No matter how advanced your transportation tech is, moving people long distances is still really costly. Sorry to "steer" this conversation into WFH and WFO topics.
We can't shift everything into remote mode. However, we don't need to hustle into physical mode every day either. Yeah, yin yang complexity, balancing everything out.
See how London deals with toob stations for pride, for example, by closing and controlling some, exit only periods close to the event, open ticket gates, etc.
Meanwhile, the integrated subway/overground/bus network in London supports direct payment with NFC smartphones, without the need for an intermediate "smart" paper ticket; the infrastructure for vending those; or the (not insignificant) cost of producing the tickets. Not sure what Montreal was thinking!
The only advantage to having Oyster is if you’re travelling enough to justify a monthly pass (daily and weekly caps are respected on bank card taps), or longer.
I travel a lot across North America and EMEA, always glad to get home and deal with London’s transport network: it’s the only one that is really designed around, built for and feels invested in the passenger experience.
30 years ago you could kill ducks with the NES guns instantly and it worked by detecting pixels.
I'm sure we can figure out how to analyze black squares and turn them into a number under 50ms.
No variance.
People can then use nfc with their phone, which doesn't have the pollution problem.
I'm all for the "we have technology why tf don't we use it, why aren't we better at it" argument, but the truth is that a lot of tech/systems in transport & other areas are retro af and new stuff gets shoe-horned in with all the caveats of a shoe-horning in.
Stuff doesn't get upgraded often, because it's expensive, because all of us vote for politicians that grant expensive/overpriced gov contracts putting money into them and their mates' back pockets. We'd be able to refresh public use tech all the time if it was non or low profit, never gonna happen tho.
Look at how much it cost Wales to change 30mph signs to 20mph: 34m£! And that's just for a few small areas, not everywhere they wanted to do. How in the f u c k, do you spend 34m taking down and putting up some signs? Those are ludicrous prices & all of us just completely ignore it bc we're too busy arguing about skin colour, which sex the person I sleep with is, or trans people being in the bathroom they want to be in, etc. Honestly.
None of that matter. QR code can be read on any angle because of the 3 position detection patterns it comes with, by design.
Lighting conditions are not a problem on tickets (which is what the article is about) because you can illuminate the paper from the camera.
QRCode were fast on assembly lines two decades ago. They were invented in the nineties, at a time where we had slow processors and shitty cameras.
Assembly lines give you GREAT control over where the code is located, how it's lit (consistently), and what you do on read error (can't shunt off the passenger to a read error bin, so they don't hold up the line). Rotational angle doesn't matter, perspective skew does. And then - it's a leaf of paper, so you get folds and obscured parts (yes, correctable...up to a point).
We can create live deep fakes or detect complex objects in live feeds of random webcams.
We certainly can correct a few shadows and distortions on a flat piece of paper we formatted, showing a basic symbol we designed and printed, pushed against a sensor we control, on a device we can light and shape the way we want.
NFC fails as well, you can fold the ticket just and it will break the antena.
Of course if it's a reusable ticket on a rigid medium, it won't happen. But neither for QRCode.
QR Codes were invented by Denso (automaker own) / Toyota. For high speed assembly line processes. Lul.
I don't think people realize how limited the hardware was at the time.
They think because their phone is slow at scanning QR codes, that's how it must be. But the phone is not a dedicated device for QRCode scanning.
It's like someone saying they get blurry pics of cars on the highway so clearly speed limits are not possible to check automatically.
Differentiate nomal daily sales rates within the test day, observe the trend year by year. Sounds naive, would be lovely if it works.
It's not necessarily a matter of education: just the feeling of "not worth freeloading (at the price), I'm likely to get caught anyway" is sufficient.
IMHO, if you have fare gates they need to be tied into a parent control system so that parents to limit where their kids are allowed to go alone. I've never seen the implemented and the details are important to get right.
I didn't use it that much, but did see ticket checks on one of the trips, nobody was without one.
I'll likely mangle the explanation but this sort of policy does not fair well when there is a large divide between have/have-not and little/no social safety net.
If you are poverty level you will be forever stuck in this cycle: Ticket/fine, court, loss of income, etc. What might work is simply granting free access below a certain income threshold.
Also a program for free rides to places like abuse shelters (for all genders - battered women is sexist talk!), voting booths and others similar locations should be in place - if you are going to one of them the checker verifies that are on the direct route to such a place and gives you a ticket - once you get there they validate your ticket - while if you don't arrive they send the police looking for you (in the case of abuse not arriving is a sign of urgent trouble, in other cases the police can arrest you when they feel like it)
The solution to bad behavior shouldn't involve cutting off poor people from basic services they need to improve their condition.
I was on a plane recently and two people in the row behind me were having a lengthy moan about their respective travel experiences / disasters. They stopped escalating when one of them said "That's nothing, we were just coming in to land when the volcano started to erupt."
I was really tempted to stand up and pitch in with a line about landing in Tokyo when Godzilla chose that precise moment to attack, but the fasten-seatbelts sign had just lit up, so I didn't.
Last year I bought a friend a ticket from Avon (just south of Paris) to Charles de Gaulle. I rode along and we stopped for lunch in Paris.
He carried on to the airport, met mr. Ticket man, and got a €100 fine for taking the route printed on his ticket, but too slowly.
I can’t understand what they’re trying to incentivise by doing this to tourists.
Yes, in high trust societies, you can do things like this.
Today we have to lock deodorant and toothbrushes behind bars in our pharmacies so it's not looted. We are not the same.
I have visited Prague in 2019 and their subway had no barriers, ticket machines were tucked somewhere in the corner so that I had to actively look around. Interestingly the metal poles where sticking out of the floor up to waist height with a spacing like that they used to have validators on them before.
Since I had a 3 day ticket and I validated it on the bus when going from the airport I didn't need a validator. Their trams and buses had validators in usual places, so subway probably has them too but not in an obvious place or the ticket machines already print ticket with time on it so you don't need to validate it.
i think you can buy a transit payment card if you need one.
no paper tickets. cool ephemera but pretty wasteful.
would be pretty cool if/when we see a day where provably private cryptocurrency microtransactions allow for both real privacy and the 7 day fare cap feature.
Anyway with OMNY.
You just buy a OMNY card and load it with cash if you want privacy. They are being slow to roll the vending machines for these out due to vendor issues but it's growing and they can't discontinue the MetroCard until they have all the vending machines in place.
monero is a counterexample to this.
i wonder how many organizations that do payroll see a timestamp and location when you tap a credit card at an omny reader?
maybe it's fine and can be solved with regulation, but honestly it seems a little not great.
Really leaves a good impression, knowing that they could have gouged you but chose not to.
Of course that'd mean having two recognition mechanisms, so the operator might opt for NFC and chips for single-use tickets anyway to make the system simpler. But somehow having single-use tickets with chips on them does seem wasteful to me.
There are even semi permanent ones you can buy, which are good for say 1 day, 1 weekend, or contain 10 passes.
The OPUS is also super interesting because it's a stored value card that holds the tokens on the card as opposed to a simple ID. The system was developed when cellular connectivity was still spotty, so they needed a card that would work on buses without internet access. It's pretty bad from a UX point of view though: you can only store a few different kind of fares, you can't recharge the card online (until recently you had to go to a terminal to do it, now there is a NFC phone app), you can't declare a card stolen, etc.
I think most people nowadays use a phone app rather than the card, though. But we also don't have gates at stations, and it's more of a trust and ticket inspections system similarly to what someone said about Norway.
Japan has the Pasmo system which is weird in that it's actually more like a prepaid debit-style card that you can use not only on most public transit but also as a payment method at some shops etc. You can charge it using teller machines at stations. I can't remember the details, though.
The idea that you still need single-use tickets for any use-case once you have a working transit card is just bonkers. You don't, stop making them.
I can see lots of use cases for single-use tickets. All of them are technically possible to cover with a non-disposable card, of course, but that doesn't mean single-use isn't more convenient in some of them.
Nowadays phone apps might also be an option, but that can hardly be the only way of paying for public transit.
(The optical scanning argument makes sense, however.)
Maybe that's not clear: the turnstile needs to connect to a server to check the QR. Need to only have one server, so some turnstiles will be relatively far from it. Latency.
Sure, but is this a serious design pressure? I've been on a lot of EU train and trolley networks that have a POS terminal on the train for direct sales, which are already doing networking both for the card transaction and to issue the ticket.
(Again to be clear: I'm not saying a QR is better. But I don't think connectivity is a unique problem, since systems that use NFC without tying into payment cards are almost certainly using connectivity to make up for the lack of tamper resistance.)
> To my understanding this is what most transit networks do anyways, to prevent an enterprising user from modifying their balance on the card itself.
On those on which this was attempted that I know of, this synchronization is far from instant. I was wrong in my other comment, in St Petersburg metro it only takes two hours for a dumped and restored card to be blocked, but you can apparently do this indefinitely on buses and trams because they aren't (weren't?) networked: https://web.archive.org/web/20170323213524/https://habrahabr...
The general concept is “the cost of the price”. Which is something to consider for public goods. If the prices would be zero, the cost of a ticket system would also be zero.
The majority opinion is that we all pay for public works projects even if they don't benefit us, but for some reason, transit must be self-funded. It's odd, to say the least.
It is completely counter-productive and damaging to the economy and the environment, but it is not that odd, unfortunately.
Each resident/citizen can buy a public transport card, then tie it to their Gov ID and then tap it everywhere. You could argue that this could be replaced by some vision tech but I guess this is simpler and has dual use (visitors can purchase the card and pay instead of using for free).
Makes me get out of bed and tap my phone on a specific NFC tag placed somewhere around the house, in order to turn off the alarm. Then, I may as well wake up, since I'm already out of bed : )
It's a nice companion to help perform 'habit stacking' as Atomic Habits calls it. Want to do pushups right after waking up? Place an NFC card under your workout mat, so you're forced to the mat first thing in the morning.
NFC Alarm Clock https://play.google.com/store/apps/details?id=com.nfcalarmcl... is a really great and simple Android alarm. Share if anyone has a good iOS recommendation.
Neat, but is there an advantage between this and "Place the alarm clock further from the bed"?
cries in studio apartment
But even so, I wish it would force me to key in the current time to disable, that way my sleepy brain would better understand "it's time to wake up now, because it is x time".
> It's remarkable that these NFC chips can be manufactured so cheaply that they are disposable
In our times, where we slowly understand that we have problems of resources and waste, I find it very disturbing that "disposable" is considered a positive achievement by the author.