Abstract: Recently, Wang et al. proposed a identity-based proxy signcryption scheme with forward security and public verifiability. By analyzing, it is showed that the above scheme exists some obvious errors and so it is infeasible. In this paper, based on short signature, a new efficient identity-based proxy signcryption scheme with forward security and public verifiability is proposed. It is showed that the proposed scheme’s efficiency is better than that of some existing ones under the condition of keeping the all kinds of security characteristics of proxy signcryption, so it is more propitious to applications in society.

Key words: identity-based, proxy signcryption, forward security, public verifiability

摘要： 最近Wang等人提出了一个具有前向安全和可公开验证特性的基于身份的代理签密方案，本文分析后发现其方案存在明显错误，这种错误直接导致其方案是行不通的。本文基于短签名提出一种新的高效的具有前向安全和可公开验证特性的基于身份的代理签密方案。分析表明，新方案在保持了代理签密各种安全特性的条件下，其效率高于已有方案，更适合于在实际中应用。

关键词: 基于身份, 代理签密, 前向安全, 可公开验证