普适复合水银承诺方案

Universally Composable Mercurial Commitment Scheme

水银承诺方案是一般承诺方案的一种有趣变形.水银承诺方案中增加了模糊公开阶段,模糊公开阶段不要求绑定性但是不能与真实的公开阶段冲突.普适复合安全性基本框架最早由Canetti等人提出.普适复合能够保证更高等级的安全性,比如满足普适复合性质即能实现并发安全、自适应安全以及非延展安全等等.文中提出一种普适复合水银承诺方案的构造并且在公共参数模型中证明其安全性.文中的结论一方面深化了水银承诺方案的研究,另一方面回答了Gennaro和Micali提出的一个公开问题.

A mercurial commitment scheme is an interesting variation of a regular commitment scheme, which extends to allow for a soft decommit stage. The soft decommitments are not binding but can not conflict with the true decommmitments. The original application of mercurial commitment is to construct zero knowledge sets. The universally composable framework initiated by Canetti is very useful due to its ensuring stronger securities such as concurrent security, adaptive security, non-malleability, etc. This paper proposes a universally composable mercurial commitment scheme and proves its security in the common reference string （CRS） model. On one hand, the research on mercurial commitment scheme is deepened, on the other hand the result answers an open problem presented by Gennaro and Micali.