In recent years, as blockchain adoption has been expanding across a wide range of domains, e.g., supply chain finance, digital asset, etc., the confidentiality of smart contracts is now a fundamental demand for practical applications. However, while new privacy protection techniques keep coming out, how existing ones can best fit development settings is little studied. State-of-the-art solutions suffer from limited architectural support in terms of programming interfaces, thus can hardly reach general developers. This paper proposes Cloak, a pluggable and configurable framework for developing and deploying confidential smart contracts. The key capability of Cloakis allowing developers to implement and deploy practical solutions to multi-party transaction (MPT) problems, i.e., transact with secret inputs and states owned by different parties, by simply specifying it. To this end, Cloak allows users to specify privacy invariants in a declarative way, automatically generate runtime with verifiably enforced privacy and deploy it to the existing platforms with TEE-Blockchain architecture to enable the MPT. In our evaluation on both examples and real-world applications, developers manage to deploy business services on blockchain in a concise manner by only developing Cloak smart contracts whose size is less than 30% of the deployed ones and the gas cost of deployed MPTs reduces 19%.
翻译:近年来,随着链链的采用在一系列广泛的领域不断扩大,例如供应链融资、数字资产等,智能合同的保密性现已成为对实际应用的基本需求。然而,虽然新的隐私保护技术不断出现,但对现有各种办法如何能最好地适应发展环境的研究很少。最先进的解决方案在编程界面方面受到有限的建筑支持,因此很难接触到一般开发商。本文件提议Cloak,这是开发和部署保密智能合同的一个可插入和可配置的框架。Cloakis允许开发商对多党交易(MPT)问题实施和部署实用解决方案的关键能力,即与不同党派拥有的秘密投入和国家进行交易,只需具体说明即可。为此,Cloak允许用户以说明性的方式具体说明各种变异性隐私,从而自动产生可核实的隐私运行时间,并将之运用于TEE-Block链架构的现有平台,以使MPT得以实施。在我们对实例和现实世界应用程序的评估中,Cloaks开发商设法将企业服务部署在30个障碍环节上,而其部署的智能合同则通过降低成本。