比特币白皮书解读（网络）

5. Network

The steps to run the network are as follows:

运行该网络的步骤如下：

1) New transactions are broadcast to all nodes.

新的交易向全网进行广播；

2) Each node collects new transactions into a block.

每一个节点都将收到的交易信息纳入一个区块中；

3) Each node works on finding a difficult proof-of-work for its block.

每个节点都尝试在自己的区块中找到一个具有足够难度的工作量证明；

4) When a node finds a proof-of-work, it broadcasts the block to all nodes.

当一个节点找到了一个工作量证明，它就向全网进行广播；

5) Nodes accept the block only if all transactions in it are valid and not already spent.

当且仅当包含在该区块中的所有交易都是有效的且之前未存在过的，其他节点才认同该区块的有效性；

6) Nodes express their acceptance of the block by working on creating the next block in the chain, using the hash of the accepted block as the previous hash.

其他节点表示他们接受该区块，而表示接受的方法，则是在跟随该区块的末尾，制造新的区块以延长该链条，而将被接受区块的随机散列值视为先于新区快的随机散列值。

Nodes always consider the longest chain to be the correct one and will keep working on extending it. If two nodes broadcast different versions of the next block simultaneously, some nodes may receive one or the other first. In that case, they work on the first one they received, but save the other branch in case it becomes longer. The tie will be broken when the next proofof-work is found and one branch becomes longer; the nodes that were working on the other branch will then switch to the longer one.

节点始终都将最长的链条视为正确的链条，并持续工作和延长它。如果有两个节点同时广播不同版本的新区块，那么其他节点在接收到该区块的时间上将存在先后差别。当此情形，他们将在率先收到的区块基础上进行工作，但也会保留另外一个链条，以防后者变成最长的链条。该僵局（tie）的打破要等到下一个工作量证明被发现，而其中的一条链条被证实为是较长的一条，那么在另一条分支链条上工作的节点将转换阵营，开始在较长的链条上工作。

New transaction broadcasts do not necessarily need to reach all nodes. As long as they reach many nodes, they will get into a block before long. Block broadcasts are also tolerant of dropped messages. If a node does not receive a block, it will request it when it receives the next block and realizes it missed one.

所谓“新的交易要广播”，实际上不需要抵达全部的节点。只要交易信息能够抵达足够多的节点，那么他们将很快被整合进一个区块中。而区块的广播对被丢弃的信息是具有容错能力的。如果一个节点没有收到某特定区块，那么该节点将会发现自己缺失了某个区块，也就可以提出自己下载该区块的请求。