Will Dance For Bitcoin

Bitcoin Bot

It seems that Bitcoin is all over the news nowadays, but the Bitcoin Bot is probably the first robot that will dance for Bitcoins.

[Ryan] at HeatSync Labs in Mesa, AZ, is a fan of the cryptocurrency, and decided to build something to accept it. He discovered that Coinbase, a popular hosted Bitcoin wallet service, has a callback API. This causes Coinbase to fetch a specified URL any time a wallet receives a transaction, and provides information on the transaction in the request. A Python script handles these requests and updates a running count of the BTC balance sent to the robot’s wallet.

On the hardware side, an Arduino with an Ethernet Shield checks the balance. If it has changed, it calls the dance function and the luau girl dances.

The robot sits in the window of the hackerspace, so anyone passing by can read about Bitcoin and make a donation. The source code is on Github, and a video follows after the break.

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Stealing $100 Million in Bitcoins

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In early October of this year, online Bitcoin marketplace and ‘the eBay of drugs’ The Silk Road was taken down by the FBI. Just after the black vans took Silk Road head honcho [Dread Pirate Robberts] away, a new Bitcoin marketplace came onto the scene called Sheep Marketplace. Sheep Marketplace closed after revealing that 5400 bitcoins – or $5.8 million USD were stolen by the user EBOOK101 by exploiting a bug in the Sheep site.

Over this last weekend, it was revealed this bug in the Sheep Marketplace site wasn’t responsible for the loss of 5,400 coins, but instead 96,000 BTC, or $100 million USD, making this one of the largest thefts of all time.

Whoever was responsible for this theft didn’t make a clean getaway. Because the Bitcoin block chain records the history of every transaction, laundering bitcoins is harder than it seems. The most common method is to ‘tumble’ the bitcoins – sending them through multiple wallets, combining and recombining them, until tracking groups of bitcoins just becomes too hard.

[sheeproadreloaded2] over on Reddit managed to track these bitcoins to this bitcoin address, an amazing feat that also means there are 96,000 coins in a wallet somewhere that can’t be spent or cashed out without the thief telling the world who he is.

As far as crimes of the century go, this one is at least in the top ten. Unless the thief behind this heist is extraordinarily smart, though, his identity will most likely be found out eventually.

A Bitcoin vending machine

bitcoinVendingMachine

Accessibility is one of the biggest hurdles facing the Bitcoin revolution, so [Mathias] found a way to give BTCs some market penetration by converting an old condom vending machine. The machine was 30 years old and required some clean up. [Mathias] also worked in a plywood adapter that attaches to the mount on the back so it can install on a wider variety of surfaces. This is an electricity-free alternative to selling coins: the machine is purely mechanical and it vends custom-made vouchers rather than the coins themselves, which you then redeem on the Kondocoin website.

The transaction isn’t as instant or snazzy as the Bitcoin briefcase converter from Defcon this year, but it still provides the advantage of an up-to-date exchange rate, as the vouchers themselves are valued at amount of Euros spent rather than a set amount of coins. The exchange rate is consulted later, when you punch in your voucher key. [Mathias] wants to share the wealth, too, and offers up the server software on github along with a detailed explanation of the process.

Put in pocket change, get bitcoins

bitcoin

[gbg] put together a neat little project to get people familiarized with Bitcoins. A lot of techies know what Bitcoins are, but the impetus to download the Bitcoin client and start mining is a bit too much for some. [gbg] has a solution for this – a Bitcoin vending machine. Just dump your pocket change in the coin slot, and out comes a QR code that allows you to add Bitcoins to your wallet.

Inside this Bitcoin briefcase is a Raspberry Pi that connects to a local WiFi connection. Every five seconds, the Raspi looks at the current conversion rate of USD to Bitcoins. Once coins are deposited into the briefcase, a receipt complete with a scannable QR code is printed on a small thermal printer.

When [gbg] took this to the latest DEFCON, a lot of people were interested in the project and started shoveling change into the machine. So many people were interested that [gbg] and his compatriots are planning on turning this into a proper open-source device, complete with a bill reader and possibly an ASIC miner so the Pi can sell the coins it produces.

Check out the video below for some more info.

[Read more...]

Raspi Bitcoin miner may just pay for itself eventually

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We’re sure a lot of people out there have a Raspberry Pi or two lying around waiting for a project to come to mind.  [Dave] has an interesting solution to this orphaned hardware – use it to mine Bitcoins and perhaps put a few extra bucks in your pocket at the end of the year.

[Dave] is using a Raspberry Pi, powered USB hub, and an ASICMiner Block Erupter to do Bitcoin mining at 330 Megahashes per second. There are a few ancillary items such as a case and USB fan, but if you already have a Raspberry Pi, you’re only looking at a $50 USD investment to have a dedicated Bitcoin miner.

According to this Bitcoin mining profitability calculator, with a $50 investment that can mine at 330 MH/s, you’re looking at a hardware break even point of about 120 days. You could cut that down to just a few months if you overclock your ASICMiner, but it’s still relatively late in the game for amateur Bitcoin miners to make a substantial amount of money. Think of Bitcoin mining as more of hobby, and you’ll hopefully be more realistic about your goals.

Overclocking your Bitcoin miner

bitcoin

The name of the game in mining Bitcoins isn’t CPUs, GPUs, or even FPGAs. Now, hardcore miners are moving on to custom ASIC chips like the Block Erupter, For around $100 USD, you too can mine Bitcoins at 300 MH/s with 2.5 Watts of power and a single USB port. This speed isn’t enough for some people, like [Jeremy] who overclocked his Block Erupter to nearly twice the speed.

[Jeremy] begins his tutorial with a teardown of the Block Erupter hardware. Inside, he found a custom ASIC chip, an ATTIny2313, a USB UART converter, and a voltage regulator for the ASIC. By changing out the 12 MHz crystal connected to the ASIC and fiddling with the voltage with a trim pot, [Jeremy] was able to overclock the ASIC core from 336 MHz to 560 MHz. Effectively, he’s running two Block Eruptors for the price of one with the potential to actually make back the purchase price of his hardware.

It must be noted the 560 MHz figure comes from replacing the 12 MHz crystal with a 20 MHz one, and this mod only lasted about 20 minutes on [Jeremy]‘s bench until the magic blue smoke was released. He recommends a 14 or 16 MHz crystal, netting a new speed of either 392 MHz or 448 MHz for a stable mod.

Trust hacking: How the Bitcoin system works

how-bitcoin-network-functions

[Scott Driscoll] sent us a link to his Bitcoin explanation a couple of weeks ago. We glanced at it but moved on rather quickly. It’s been popping up here and there and we finally gave it the time it deserved. This video is interesting in that it doesn’t just focus on what the Bitcoin actually is, but how the Bitcoin system works when it comes time for money to change hands.

Quite early on in the explanation he mentions that “The Bitcoin system is amazingly designed so that no trust is needed”. That’s a powerful statement. For instance, if you sell your car, one of your friends will probably tell you not to take a check. That’s because a check means you’re trusting that the buyer actually has a balance in their account to cover the transaction. With Bitcoin the transaction carries its own proof that the currency is available by including information about the past transactions through which those Bitcoins were acquired.

If you have some idea of what public/private key pairs are you’re already equipped to understand [Scott's] lecture. After you make it through the 22 minute video maybe you should get down to work doing some Bitcoin mining at home.

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