一段程序看懂比特币原理
jopen 11年前
自从比特币火起来以后,网上对比特币的解释可谓汗牛充栋,纷繁复杂。但对于程序员来说,最直接的方式莫过于直接看程序代码了。嫌比特币代码庞杂没关系,我找到一段简明扼要的代码,用来理解比特币再好不过了。
以下这段程序转自知乎上 Wu Hao 的回答。
function mine () { while(true) { longestChain = getLongestValidChain () -- A number that changes every time, so that you don't waste -- time trying to calculate a valid blockHash with the same -- input. nonce = getNewNonce () currentTXs = getUnconfirmedTransactionsFromNetwork () newBlock = getNewBlock (longestChain, currentTXs, nonce) -- http://en.wikipedia.org/wiki/SHA-2 -- and this is what all the "mining machines" are doing. blockHash = sha256(newBlock) if (meetReqirements (blockHash)) { broadcast (newBlock) -- Now the height the block chain is incremented by 1 -- (if the new block is accepted by other peers), -- and all the TXs in the new block are "confirmed" } } } ////////////////////////////////////////////////////// function sendBTC (amount) { sourceTXs = pickConfirmedTransactionsToBeSpent (amount) tx = generateTX (sourceTXs, targetAddrs, amount, fee) signedTx = sign (tx, privateKeysOfAllInputAddress) broadcast (signedTx) } ///////////////////////////////////////////////////////////////
下面是我的解释:
挖矿过程就是不断从比特币网络中获取所有未确认交易getUnconfirmedTransactionsFromNetwork ()
,把它们打包成一个区块并挂载目前最长的区块链上getNewBlock (longestChain, currentTXs, nonce)
,然后计算新的区块的散列值sha256(newBlock)
,如果散列值正好满足挖矿难度了meetReqirements (blockHash)
,那么就挖矿成功了。所谓挖矿难度,指的是要求的二进制散列值末尾 0 的个数,而散列值是碰运气生成的,除了穷举没有别的办法,要求的 0 个数越多挖矿的难度就越大。
付款过程就是把一些有余额的已确认交易拿出来作为发送地址pickConfirmedTransactionsToBeSpent (amount)
,然后根据目标地址支付一定交易费生成新的交易generateTX (sourceTXs, targetAddrs, amount, fee)
,并用钱包私钥对交易签名sign (tx, privateKeysOfAllInputAddress)
,然后广播出去。
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