无可信中心的可公开验证签密方案

摘要

Most ID-based signcryption schemes with public verifiability have security problems because of key escrow. So this paper proposes a public verifiable ID-based signcryption scheme without trusted Private Key Generator(PKG). A secret value chosen by signer is added as the partial private key, so that dishonest PKG can not forge the signature of user or decrypt and restore plaintext without authorization. Security analysis shows that the proposed scheme is secure against existential forgery on adaptively chosen massage and identity attack under the random oracle model, and it has the properties of confidentiality and traceability.%可公开验证的基于身份签密方案大多因密钥托管问题存在安全漏洞.针对该问题,提出一个无可信中心的可公开验证签密方案.通过加入一个可由签名者自选并对私钥产生中心(PKG)保密的秘密值作为部分私钥,使不诚实的PKG无法伪造用户签密或擅自解密恢复明文.分析结果表明,该方案在随机预言模型下可以抵抗适应性选择消息和身份的存在性伪造攻击,并具有保密性和可追踪性.