电子邮件系统中支持关键字搜索的代理重加密方案

针对在加密电子邮件系统中如何搜索已加密邮件和授权他人处理已加密邮件的问题,提出一种面向电子邮件系统支持关键字搜索的代理重加密方案。利用可搜索加密技术对加密邮件进行搜索,使用代理重加密技术对加密邮件授权。安全性证明及效率分析结果表明,该方案可以更好地抵抗篡改攻击和关键字离线猜测攻击,同时,在标准模型下,证明了该方案在判定Diffie-Hellman问题、双线性判定Diffie-Hellman问题、商判定Bilinear Diffie-Hellman问题上,分别满足陷门隐私安全、关键字隐私安全和密文隐私安全。相比dPRES方案,该方案减少了时间开销,提高了搜索效率和解密效率。

Proxy Re-Encryption Scheme Supporting Keyword Search in Email System

To authorize others to deal with encrypted mails and enable the search of encrypted mails in an encrypted email system,this paper proposes a proxy re-encryption scheme that supports keyword search for email systems.In this scheme,searchable encryption technology is used to search encrypted mails,and then proxy re-encryption technology is used to authorize encrypted mails.Security certification and efficiency analysis results show that the proposed scheme can better resist tampering attacks and keyword offline guessing attacks.At the same time,under the standard model,it is proven that the scheme respectively meets trapdoor privacy security,keyword privacy security and ciphertext privacy security in the determination of the Diffie-Hellman problem,the Decisional Bilinear Diffie-Hellman(DBDH)problem,and the Quotient Decisional Bilinear Diffie-Hellman(QDBDH)problem.Compared with the dPRES scheme,the proposed scheme reduces the time cost and improves the efficiency of search and decryption.