SaTC: CORE: Medium: Proactive and Reactive Mechanisms for Safer Smart Contracts

智能合约是自主执行可以操纵数字资产的程序。它们的关键功能是创建可信的交易环境：它们可以以对所有各方公平的方式执行任意复杂的协议。智能合约有望产生变革性的社会影响，为金融、数字媒体和保险等不同行业带来全新的效率。然而，智能合约成功部署的一个障碍是它们对漏洞的高度敏感性，这可能直接导致违反合同义务，甚至盗窃资产。因此，需要新的方法来确保智能合约的可信度。本研究项目从两个方面解决了智能合约中的可信度问题。它探索了新的、主动的、基于语言的机制，以增加契约在部署之前正确实现的保证。然而，并不是所有的错误都能在部署之前被发现，因此该项目还研究了防止和减轻由错误编程的智能合约造成的损害的反应机制。本研究中探索的反应性方法包括有原则地使用bug奖励来激励发现和报告bug，再加上内置的缓解机制，在发现bug时改变合约行为。这项研究的成果将包括适用于更广泛的软件保障问题的智能合约保障的新科学基础，以及结合主动和被动工具以在部署的智能合约中实现更高可信度的实用方法。

Smart contracts are autonomously executing programs that can manipulate digital assets. Their key capability is the creation of trustworthy transaction environments: They can execute arbitrarily complex agreements in a manner that is fair to all parties. Smart contracts promise to have a transformative societal impact, bringing radical new efficiency to sectors as diverse as finance, digital media, and insurance. An impediment to the successful deployment of smart contracts, however, is their heightened susceptibility to bugs, which can lead directly to violation of contractual obligations and even theft of assets. Thus, new ways of ensuring the trustworthiness of smart contracts are needed. This research project attacks the problem of trustworthiness in smart contracts from two sides. It explores new, proactive, language-based mechanisms for increasing the assurance that contracts are correctly implemented before deployment. Not all errors can be caught prior to deployment, however, so the project also investigates reactive mechanisms for preventing and mitigating the damage caused by incorrectly programmed smart contracts. The reactive methods explored in this research include the principled use of bug bounties to incentivize discovery and reporting of bugs, coupled with built-in mitigation mechanisms that alter contract behavior when bugs are uncovered. The outcomes of this research will include new scientific foundations for smart contract assurance that are applicable to the broader problem of software assurance, as well as practical methods that combine proactive and reactive tools to achieve heightened trustworthiness in deployed smart contracts.