基于时代可撤销的变色龙哈希

Epoch-Based Revocable Chameleon Hash

变色龙哈希函数是带有陷门的单向哈希函数,现已成为实现可编辑区块链的主要技术。为解决可编辑区块链中变色龙哈希函数陷门滥用的问题,提出了基于时代可撤销的变色龙哈希函数,其中一个时代为一个具体的时间周期。该函数使得陷门具有时效性,将随时代变更失效,以达到撤销陷门的目的。定义了其安全模型,并给出了具体的方案实例,方案在标准的困难假设下被证明是安全的。理论分析和实验表明,相比于同类型的方案,所提方案在安全性上具有优势,且具有较小的额外开销,具备一定实用性。

Chameleon hash,also called one-way hash with trapdoor,has now become the primary technology for implementing redactable blockchain.To solve the problem of trapdoor abuse of chameleon hash in redactable blockchain,the epoch-based revocable chameleon hash is proposed,where one epoch refers to a specific time period.This function makes the trapdoor time-sensitive and invalid as time changes,so as to realize the purpose of revoking the trapdoor.Also,its security model is defined and specific scheme instants are given.The instants are proven to be secure under standard difficult assumptions.Theoretical analysis and experiments show that compared with the same type of scheme,the proposed one has advantages in security with a small extra cost,showing its practicality.