Bitcoin mining with FPGA

speaker: Alex Teo, D’Crypt event: Friday Hacks #3, NUS Hackers ** bitcoin basics

• accounts are public-private key pair
• public ledger stored in append only ordered block chain
• authoratative chain is one with most cumulative work done prevent double spending by proof of work
• incentive to mine by giving successful miner bitcoins after there are 21 million coins, incentive is transaction fee ** D’Crypt raptor high performance FPGA platform 10 x Raptor blades, each has Stratix IV FPGA there is a chassis control computer ** using BFGMiner in BTCGuild mining pool ** mining details 640bit header + 32bit nounce sha-256(first 512 bits of header) = midstate (constant) sha-256(second chunk of header + nounce) = round1 output sha-256(round + midstate) = final hash compare final hash with difficulty threshold ** achievement
• hashrate of 1.5 GH/s, about 1.5 BTC/day at its heyday
• efficiency of 15 MH/J