加密邮件系统中基于身份的可搜索加密方案

在加密邮件系统中，公钥可搜索加密技术可以有效地解决在不解密的情况下搜索加密邮件的问题。针对公钥可搜索加密复杂的密钥管理问题，该文在加密邮件系统中引入了基于身份的密码体制。针对可搜索加密的离线关键字猜测攻击问题，该文采用了在加密关键字和生成陷门的同时进行认证，并且指定服务器去搜索加密电子邮件的方法。同时，在随机预言机模型下，基于判定性双线性Diffie-Hellman假设，证明方案满足陷门和密文不可区分性安全。数值实验结果表明，在陷门生成和关键字密文检测阶段，该方案与现有方案相比在计算效率上较高。

Identity-based Searchable Encryption Scheme for Encrypted Email System

In encrypted email system, the public key searchable encryption technology can effectively solve the problem of searching for encrypted emails without decryption. In view of the complex key management problem of public key searchable encryption, an identity-based cryptosystem is introduced in the encrypted mail system. For the offline keyword guessing attack problem of searchable encryption, the method of encrypting keywords and generating trapdoors are adopted at the same time, and the server is designated to search for encrypted emails. At the same time, under the random oracle model, based on the decisional bilinear Diffie-Hellman assumption, the scheme is proved to satisfy the trapdoor and ciphertext indistinguishable security. The numerical experiments show that the scheme has higher computational efficiency than the existing schemes in the keyword trapdoor generation and keyword ciphertext test phase.