Abstract: Trusted database based on database as a service(DAS), in which data owner(DO) stores the cryptographic data in the database service provider, and the key factor is trusted sharing key in trusted sharing data between DO and authorized users. The security of the existing key management approach depends on beforehand securely sha- ring the user key between DO and authorized users in DAS, however, which is an unsolved problem in trusted database yet. This paper proposes a trusted key distribution protocol which provides trusted sharing data between DO and authorized users based on certificateless authentication schema, and gives the analysis of validity and security. The protocol is independent to the security transmission channels and trusted third party, and is proved to be security based on discrete logarithm (DL) problem, inverse Diffie-Hellman (Inv-CDH) problem and q-Strong DH problem.

Key words: trusted database, database as a service (DAS), trusted key sharing, certificateless, trusted data sharing

摘要： 基于DAS模型的可信数据库环境下, 数据拥有者将数据加密以后存储于第三方数据库服务提供商, 数据拥有者与被授权用户间的可信数据共享本质上是数据密钥的可信共享。现有的DAS模型中密钥管理方法的安全落脚点都是假设数据拥有者与各用户能事先分别安全共享一个用户密钥, 而在可信数据库环境下如何进行数据拥有者与用户间的可信用户密钥共享却是一个未解决的问题。基于无证书签名认证机制, 提出了一种可信数据库环境下的可信用户密钥共享协议, 并对该协议的有效性和安全性进行了分析。该协议完全无需安全传输通道和可信第三方作为支撑, 且有较好的执行效率; 同时基于DL问题、Inv-CDH问题、q-Strong DH问题等数学难题, 该协议被证明能有效抵御无证书安全模型下的各种攻击。

关键词: 可信数据库, 数据库外包服务, 可信密钥共享, 无证书, 可信数据共享