Hacker News Reader

> To achieve this, the keyboard and the display is galvanically separated for the duration of the PIN entry

Perhaps this sounds too dull to ask, but what stops the terminal from just ... not separating the keyboard and display?

Certification. Worked in the same industry, and there were very strict both hardware and software requirements for POS software. Having gone trough credit-card audits, early EMV certification programs, and certification to place non-payment software next to payment software on such systems, I can tell you - it's no joke :)

> I can tell you - it's no joke :)

But still as a user I have no idea if I'm talking to a certified machine or not.

As a user, fraud is not your problem. Security isn’t there for your benefit.

It's not your problem. For the transaction to take place it has to go to your bank and your bank trusts Visa/Mastercard to manage risks. You would be surprised to know most frauds are absorbed by banks. Nobody is interested in people fearing plastic because it causes people to increase very expensive debt plus additional interchange fee from every transaction.

Certification [...] I can tell you - it's no joke :)

I'm not so sure. "And then initial supplier inserted hardware that thwarted all those pressing considerations" sounds a punchline to me. :(.

That, at least, is a problem that cab be solved by tightening security at supplier site.

The safeties are mainly to guard against the rest of the world. For example it prevents tampering in transit, or even in our own company - disgruntled employee can't do anything.

Or think for a second about the fact that we leave the device for, hopefully, entirety if its life at the client site. We had clients that were shady businesses like strip clubs that no other companies would touch with a stick.

Those VISA/MasterCard rules can't be universal because there's at least one bank issuing merchant terminals that run Android and take the PIN on the touchscreen:

https://www.commbank.com.au/business/merchant-services/eftpo...

This only accept contact-less payment who doesn't require pincode.

PED/PTS devices have even stricter guidelines than contactless payments.

But this device doesn't need a way for the user to enter the pincode. So, all the sensitive part of the terminal is probably completely isolated from the android part.

I don't know this device internal and the PED/PTS exact requirement but it seems plausible for me.

You have something like a physical compartment who include the NFC and everything needed to process it like in a classical terminal. This compartment is highly secured as requested by the specification with just a very simple interface for the android part to send the amount to bill.

I've seen a lot of each-machine running on windows. Doesn't they work like this with the windows machine just managing the display buttons to select the amount and sending this information to the secure part who handle card interaction, pincode and delivery of the money ?

Yes this is a common design in fact most current solution segregated the POS and POI completely anything that handles the actual credit card whether it's C&P, Track2 or NFC is a closed black box with the required PED/PTS/POI and P2PE certifications the merchant never sees what's going on they only can talk to the thing in bill the next card X and get a confirmation of the transaction that's it they don't see any of the card data they don't even see any card holder data unless they collect it in a side channel e.g. a loyalty program.

Now none of these certifications or standards is bullet proof but people have a very skewed vision of the PCI certification process likely due to bias of only having interacting with the PCI-DSS requirements for merchants and low levels to boot meaning they didn't had to do anything but to fill the SAQ themselves and be on their way.

It accepts contactless payments over the threshold where a PIN is required, and does in fact prompt for a PIN using an on-screen keypad.

Those are universal PCI council rules the fact that the terminal runs android doesn't mean anything it still needs to be compliant with the PIN entry device requirements as well as PTS and POI requirements depending on the exact nature of the device:

https://www.pcisecuritystandards.org/documents/pos_ped_secur...

https://www.pcisecuritystandards.org/documents/PCI_PTS_POI_S...

The requirement for the tamper proofings is literally the first requirement in the PED standard:

A1 Vendors must comply with all components of A1.

A1.1

The PED uses tamper-detection and response mechanisms that cause the PED to become immediately inoperable and result in the automatic and immediate erasure of any secret information that may be stored in the PED, such that it becomes infeasible to recover the secret information. These mechanisms protect against physical penetration of the device by means of (but not limited to) drills, lasers, chemical solvents, opening covers, splitting the casing (seams), and using ventilation openings, and there is not any demonstrable way to disable or defeat the mechanism and insert a PIN-disclosing bug or gain access to secret information without requiring an attack potential of at least 25 per PED, exclusive of the IC card reader, for identification and initial exploitation as defined in Appendix B of the PCI POS PED DTRS

Clover CEO here. Won't comment on a competing device but this may not work the way you think. In Clover's approach the touch controller input isn't reaching the Application Processor running Android when in PIN entry mode. You can do patent search if you're interested.

That would be in line with the requirements. You go through stringent certification with the software and hardware that has access to the actual PIN and then show that the application and application hardware never really has any access to it so that you can customize/update your software.

This is the easy part.

The hard part I remember was establishing secure communication between all components in the system (initializing HSMs, injecting keys). I remember helping designing the process and writing hundreds of documents describing various security-related procedures like how the HSM racks are inspected, how the keys to the racks are fetched from the safes, how there are multiple safes for multiple security officers, how the officers are prevented from ever having access to other safes, how fetching anything from safes requires logging and using tamper-evident containers, how the logs are inspected, and so on.

I have designed a special cryptographic protocol so that we could generate and inject keys to the devices in KIF (Key Injection Facility) and separately to our database (to establish communication with the terminal). Fun.

Agree the people and process side is very difficult to do well. Familiar with all those and more -- we have extremely good, dedicated employees who care deeply about doing those things right.

We have some fun stories on this topic, like when we were using our PCI PIN approved secure room in our development office for the first time. We papered over the cage to prevent a security camera from being able to see employees entering PINs on the HSM. An eager employee papered over this cage a little too well cutting off the natural flow of air. And then there was a bug in our offline CA code and we spent 30 minutes in that air deprived cage while debugging occured :) finally the bug was fixed, we issued the cert on our first production device, and stepped out to get a breath of fresh air. Obviously this isn't our daily driver secure CA room :)

(If anyone reading is looking for a job in security engineering, we're hiring! https://www.clover.com/careers/engineering)

I have few more stories like the time when I closed the HSM rack door a bit too energetically and caused outage to entire company as we had to bring in third security officer to re-initialize it.

We also had special screens created for all cameras in the datacenter to block view on the HSM racks.

The biggest issue was, just before end-to-end test we figured out we forgot one of critical procedures (it was establishing authenticity of the HSM used) and we had to scramble to get new HSM and to re-establish all cryptographic material (so new storage keys, etc.)

404

What you're describing sounds like another backdoor of its own!

The general problem with most "industry security" approaches is that they simplistically attempt to wrestle ultimate Godmode-control for themselves, rather than working towards eliminating it.

Worked in the payment industry for years. Visa/Mastercard do absolutely nothing to verify that companies are not storing Pin codes. The HSM is required for communication with them only.

That's not correct the QSA will validate that the device does not store PIN codes or the that the merchant does not store anything they are not allowed.

Devices that accept cards need to comply with PED/PTS security requirements including very strict physical security requirements which are validated by PCI council approved laboratories and firms.

You are not getting a device on the market or usable with any merchanet network without complying with this: https://www.pcisecuritystandards.org/documents/pos_ped_secur... and a few other standards.

About that, I can only say that Chinese android POSes do everything in software, for sure, without any hsm present.

The question is, how Chinese banks coax Visa into allowing them using them.

Probably it just goes through as a card not present (CNP) transaction?

So you mean it first authenticates the pin, and initiates CNP after? Never thought of that as possible.

It's not CNP doesn't use the pin it uses the CVV2, you also can't use the chip and pin or track 2 swipe data for a CNP transaction.

I think the GP is confused on how a POS works, POS isn't a POI most of them don't touch the credit card they just talk to the reader, most readers today are P2PE closed loop solutions so the only thing the POS does is sends to the reader charge the next card $X the reader will then reply if the transaction went through or not and that's it.

The reader itself will talk to the acquiring bank or the payment provider in a point to point encrypted closed loop and the merchant would never see any credit card details.

Simple greed? As in: "play ball, and you get access to the gigantic Chinese market"

The POS and the PED/PTS isn't the same thing the POS can complete the transaction without touching the credit card in fact most of them do exactly that the only thing that it does is communicate with the PED/PTS to send the amount and get a confirmation/denial.

Second this, after having to go through a service level 1 DSS review for a few years. Lower level reviews (3,etc) just require self validation.

SAQs don’t involve QSAs. They are also intended for merchants which are a rounding error also there is no SAQ for PA, PED, PTS etc. certifications only for merchant PCI-DSS.

Wrong. PIN codes are entered into a damn mobile app and passed through an API. Billions of times per day. You guys are clearly missing the card serciving aspect of the industry.

Please show me the device that transmits the pin of a chip and pin card to an API while not being compatible with PED and P2PEE requirements.

You can totally fake your way through PCI audits. I know of a company that did it for years using a fake network and servers. Not sophisticated at all. Most auditors do not find all of the compliance violations. They have one person do it. It's all about money.

You can fake a lot of things so what? That’s not the point, also PCI DSS is pretty crappy but the hardware vendor, payment provider and P2PEE certifications are a completely different story good luck faking it.

Sure you can send fake devices to be certified and sell something completely different but the same can be said for any certification and if you get caught boy or boy...

That's not correct.

HSMs are required so that the company does not need to have PIN codes exposed anywhere. Not having PINs or full credit card data makes your life easier as there is nothing to steal from you in the first place.

If your company stored PIN codes it means you were in breach of the contract and it had to lie to the auditors to pass the certification.

"If someone was going to break the law, they would have to lie about it first."

Legit companies don't want the info and anyone that wants the info isn't doing anything legal with it.

It is correct. Incompetence abounds. You are correct about the HSM but it does not enforce anything except for the exchange between whoever and MC. You do realize that pin codes are entered into a UI and phone system as plain text right? There are PCI audits but they are a joke.

You realize when we talk pins we mean authorizing your credit card chip&pin transaction? Nothing to do with your phone pin or maybe som other pins.

The pin we are talking about is what is customized on your credit card (directly in its memory) or its equivalent in your bank's HSM for the sole purpose of performing CVM step negotiated by yor card and payment terminal.

But in the US we just use signatures for card transactions instead of chip PIN :/