Bitcoin Vending Machine | Hacker News Reader

Bitcoin Vending Machine

blog.maschinenraum.tk

131 pointskiba36 comments

Note the carton it comes out in; the bitcoin receipts are printed out ahead of time, and stuffed into the vending machine like a pack of cigarettes.

A more advanced vending machine would purchase the bitcoins in real time, with the correct exchange rate, and print out the receipt on the spot. That would actually be pretty cool! Especially to think about security; you can rob a standard vending machine, but you can't steal it, disassemble it, and trick it into ordering thousands of bitcoins.

While just as functional (assuming a stable exchange rate), this particular device has zero notability as far as cool hacks go. It's a bog standard vending machine with bitcoin für euro painted on the side.

I think the key thing to note is that it's an art project - perhaps the intention of mixing an old school style dispenser system with a high-tech currency was the intention.

Also a great way to introduce people to bitcoin. With this, users can scan the URL to their mobile (iPhone/Android), bookmark it and within a couple of minutes also send bitcoins from their mobile to friends mobile.

You're right, the main idea was to introduce people to Bitcoin in general. Right now putting in that coin, scanning the code, pasting and address and pressing the send button is the easiest way to donate to wikileaks from Germany :) The mechanical aspect was 'decided' by the constraint of having it ready for the exhibition. Snapping a used machine of eBay and manually filling it with boxes was the only feasible way, although I started with the idea of a super fancy ATM-style machine.

Can you send the bit coin to yourself?

Of course, you can send it to any address. This address could belong to wikileaks, me or yourself or anybody.

Declaring it has zero notability as far as cool hacks go is highly subjective. I for one think this is much cooler then the usual CRUD to-do list webapps we see around here so much.

I like the cut of your jib

IMO the charm is that it looks like a condom machine in a toilet.

Hi, artist here. I want to use the moment of attention to ask around for ideas on how to conceptually build the reverse of this. The current idea would be to also use a web wallet, ie. you would preload an easywallet.org wallet with some coins, then give the URL to the machine (type, QR, whatever) and it spits out cash. There must be something more clever to solve the problem of transaction verification (inside easywallet it's instant and we don't have to wait 10m) and authentication (if the machine would receive your bitcoins on a special address, how the machine know you sent it?).

There are NFC bitcoin wallet apps for android aren't there? And "POS" NFC apps? Just cram an android board and an NFC reader in it set to accept taps, look up the exchange rate and spit out cash.

NFC has 0 users in my area, so later on this would be an option. But what about something right now, not involving complicated tech?

Bitcoin probably has less users in your area than people with NFC capable phones. I think for an art project this is a non-issue.

I also think if you consider my solution so "complicated tech" then this probably isn't the project for you.

You would probably have to give people a unique address to send coins to, along with a corresponding secret code to use for their withdrawal.

As an aside, how do you generate the QR code? Do you have to create a separate wallet?

The value of 1€ is stored in a seperate wallet. The QR code is the link to the URL of this web wallet.

If there was a moment to use QR codes for something useful it would be that receipt. The last thing I want to do is type some 34 character case-sensitive id into my browser to get my money.

On your phone, no less.

I'm still stunned that Microsoft and their Kinect wizardry can't scan those XBL codes so you don't have to waste so much time typing them in. QR codes have a use!

The inconvenience is part of their business plan. A certain percentage of people won't redeem their code, making it profitable.

Most of the codes I've redeemed are for things that come bundled with something I've already purchased.

I doubt typing in an annoying code is going to make a meaningful difference in the redemption percentage of purchased point or Live cards. The biggest factor there is losing track of them.

There is a QR code on the receipt, it is just hidden under the small box so the internets does not steal my 1 €.

Send the E to your main wallet and show to QR code.

It would be quite intresting to watch later the statistics of access

Your €1? Seriously? If you really cared about €1 you'd obfuscate the ID, and put a bogus QR, but geeze, €1? I suspect in reality that while you were busy sticking paper labels to a pub condom machine with blue-tack you forgot the obvious utility of a QR code on the ticket.

Is there any way a practical Bitcoin ATM could be done? I.e. a machine where you can get cash Euros/Dollars/Gold from your bitcoins. The naive approach is it just has an address you send BTC to, but then you have to stand around for 30 minutes while the transaction is verified.

Something like that, but it could be done ahead of time - receive a bitcoin address & redemption code online, send your coins then ~30mins later go to the machine, enter your redemption code and receive your BTC.

Redemption code could also be a QR code. Put it on your phone & hold it up to the machine.

You can instant accept any bitcoin value that is lower to the investment to do the 51% attack or similar. Example: no one is going to make a 51% attack to steal only 10 bitcoin from a vending machine.

Simply put a limit, or just say to the user that any amount of bitcoin over X will need Y time to get verified. Anything lower that X amount will be instantly processed.

Doesn't it require ~10 minutes to solidify into the record to prevent double-spending without having the 51% attack?

Correct - there are various attack vectors besides the 51% attack. Ideally, a transaction shouldn't be closed until there have been 2 confirmations.

One was previously announced - seems to now have been made open source as well: http://bitcoinatm.com/

It would be interesting for a retailer/restaurant to have a Bitcoin ATM on-premise and offer a discount for people who paid that way.

I still think NFC proliferation would be a great thing for Bitcoin.

This reminds me of the fingerable Coke vending machine of 1982 (http://www.cs.cmu.edu/~coke/history_long.txt).

You should definetely use QR Codes if you want to print it on paper. I think a "secure enough" ID would be really a hassle to insert into your browser just with your fingers. Or you sell small USB sticks with just enough flash to store your link on it (in which case increasing the minimum to 10€ would make sense).

Or maybe I'm just too simple minded and you have some creative ideas to make your IDs secure and handwritable for my Grandma?

I thought this would be a vending machine that would accept bitcoins. That would have been more interesting

Funny how the inverse would not work.

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