引言

搭建好了github的网站发现百度和谷歌搜索都不收录，甚为沮丧，研究后发展其实有很多实用的技巧可以优化网站搜索，特写文章总结之.

应好友zesing和ivan的邀约，决定写一篇最近在伦敦的游记，本想用英文装一下，纠结了很久之后，决定还是用中文写，下面用文字和图片记录下在伦敦美妙的3天。（此刻的心情：写游记真是一件十分痛苦的事情，因为不知道写成什么文体，不由自主想写成论文的格式，摘要，引言，叙述。。。。）

第一天下车后，对于一个资深的大学历史研究员而言，最开心的事情莫过于在地铁出口看到了伯大的广告

引言

你需要上网，你在浏览器中输入一个网址，实际是你和服务器之间的沟通，两者之前需要沟通，就要知道两个的位置，IP就是用来标记你的位置的，告诉外部网络，你是谁？我以什么样的方式与外部通信，IP的地址是怎么样划分的，IP不够用的时候怎么处理，带着这些问题，开始本文的阅读。
你可以通过百度直接输入IP查询你是谁？

Abstract（摘要）

A purely peer-to-peer version of electronic cash would allow onlinepayments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that can not be changed without redoing the proof-of-work. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they’ll generate the longest chain and outpace attackers. The network itself requires minimal structure. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will, accepting the longest proof-of-work chain as proof of what happened while they were gone.

最近在学校做的一次3分钟的英文技术分享，本着厚颜无耻的态度还是把它分享出来了，讲的非常浅显，但区域链确是未来分布式数据发展的方向。

开场

Diffie-Hellman密钥交换

Diffie-Hellman密钥交换是RSA之前的算法，其中的原理就是单项函数，如下图所示
在已知下图的模式下，任意跟换X可以获得不同的输出，但是从输出你无法获取X，RSA的算法基石