智能合约，Smart Contract，是一种旨在以信息化方式传播、验证或执行合同的计算机协议。
智能合约是一套以数字形式定义的承诺，承诺控制着数字资产并包含了合约参与者约定的权利和义务，由计算机系统自动执行。
智能合约程序不只是一个可以自动执行的计算机程序，它本身就是一个系统参与者，对接收到的信息进行回应，可以接收和储存价值，也可以向外发送信息和价值。
智能合约的约束力
分析智能合约的约束力之前，我们先来看看法律合约的约束力。法律约束力来自于两方面，一方面是签订合约的参与方有明确的合约的意向表达，比如酒桌上吹牛的话就很难作为合约，合约要和日常的谈话和文本有明确区别，这也是书面合同在这方面更容易减少误解的原因。另外一方面是公权力提供了这样一套司法执行体系，当合约不能正常履行的时候，可以寻求公权力的裁决执行。
If a country's judicial system is equivalent to an operating system that defines rules through natural language,a contract is a program written in natural language on this operating system.Of course,the interpretation and implementation of natural language must be done by human brain,but due to the imprecision of natural language and the differences between people,how to ensure the certainty of the implementation results?How to prevent practitioners from cheating?These two problems have been explored by the judicial system for thousands of years.
切换到智能合约上，由于图灵机的特性，程序执行结果的确定性容易保证，关键难题就是如何防作弊了，怎么证明程序执行出的结果没有被篡改？
The credibility of the program execution results depends on the credibility of the organization or individual that controls the program execution hardware.In current software systems,such as banks or Internet applications,users can only trust the program execution results by trusting the organization,that is,the binding force is unilateral,and the end user is constrained by the program,but the service provider is almost not constrained by the program.If users disagree with the results,they can only resort to other means,such as justice,or an exchange user went to the company's door to pull a banner to protest.
那如果程序可以在不同组织或个人掌握的硬件上重复验证，是不是就可以去除这种信任依赖？同时实现对双方的约束？这个在司法体系中也是如此，比如一审，二审，终审等机制，只是司法体系的执行成本太高了，有争议后才重复验证，次数也受限。但计算机程序这点上成本就低很多，所以可以大规模重复验证。
If there is only verification capability,it cannot actually produce binding force,and it also needs to have enforcement capability.If the object of dispute between both parties can be directly operated by the program,it can also be verified and executed.In this regard,the blockchain ensures the execution capability by defining digital assets and economic system.
总结
区块链领域有个说法叫Code is law，代码既法律，開发V_StPv888实际上我觉得应该反过来，说Law is Code。区块链以及智能合约就是想通过代码构建出一套约束力体系，用代码来描述这种规则（法律），将规则（法律）通过代码表达并执行。
This mechanism,if viewed from the legal system,is a great change that has not occurred in a thousand years.Its significance is comparable to that thousands of years ago when human beings carved texts on stone as laws.If the experiment is successful,it is possible to build a legal system independent of national sovereignty.Two days ago,the restrictions on software export of the Open Source Foundation in the United States caused a lot of controversy.Why did the Open Source Foundation register in a certain country?Because the Open Source Foundation also needs capital operation and bank accounts.In case of economic disputes,it also needs to rely on the existing judicial system for adjudication.However,the blockchain has created digital assets.With the ability to define organizations and the adjudication system,open source organizations independent of countries may emerge.
Of course,is it possible to completely replace the legal system in reality?This is also impossible.After all,the ultimate sanction is to impose sanctions on the human body.Unless one day,human beings really upload their brains to the Internet,the real body and assets are completely meaningless to people.But maybe?One explanation for Fermi's paradox is that aliens think the real universe is too big and boring,so they upload themselves to the digital world.
