区块链环境下支持隐私保护的数字权限管理

针对数字权限保护中对数字内容安全和用户隐私保护的需求，提出了一种支持区块链环境下隐私保护的数字权限保护方案，设计了区块链环境下数字内容权限全生命周期保护和用户隐私保护的框架，主要包括内容加密、许可授权和内容解密3个协议。利用Diffie-Hellman密钥交换和加法同态加密算法，实现了内容加密密钥的保护和分发，同时保证了内容加密密钥的安全性和用户的隐私性，防止区块链中的其他节点收集用户的敏感信息，如用户的使用习惯。与传统的数字权限保护方案相比，该方案基于区块链具有信息公开透明、信息不可篡改等特点，并且保护了内容安全和用户的隐私，具有较好的实用性。安全性分析表明，该方案在区块链环境下是安全的；仿真实验结果表明，该方案能够以较低的开销实现用户的隐私保护。

Digital Rights Management Supporting Privacy Protection in Blockchain Environment

Aiming at the requirements of digital content security and user privacy protection in digital rights protection, a digital rights protection scheme supporting privacy protection in blockchain environment is proposed. The framework of digital content right full life cycle protection and user privacy protection in blockchain environment is designed, which mainly includes three protocols：content encryption, permission authorization and content decryption. By using Diffie-Hellman key exchange and addition homomorphic encryption algorithm, the protection and distribution of content encryption key is realized. Meanwhile, the security of content encryption key and the privacy of users are ensured, and other nodes in the blockchain are prevented from collecting sensitive information of users, such as users’ usage habits. Compared with the traditional digital rights protection scheme, the scheme based on blockchain has the characteristics of open and transparent information, information can not be tampered with, and protects the content security and user privacy, so it has better practicability. Security analysis shows that the scheme is secure in the blockchain environment; simulation results show that the scheme can achieve user privacy protection with low cost.