Abstract: There are some problems in traditional digital rights protection system, such as centralization, opaque transaction information and authority information. A digital rights protection system based on blockchain is proposed by using the advantages of decentralized and transparent blockchain technology. The system uses interplanetary file system（IPFS） to store encrypted digital content, completes permission transaction and automatically issues license through smart contract, and records permission transaction information and license information by blockchain. It solves the problem of single point of failure caused by centralized content server in traditional digital rights protection system, realizes the license issuing function and rights trading function without any centralized server, and ensures the transparency and credibility of information. The analysis of security and performance shows that the system is safe and feasible; the simulation results show that the system can realize the rights protection of digital content with low cost.

Key words: blockchain, smart contract, interplanetary file system（IPFS）, ethereum, digital rights management

摘要： 传统的数字权限保护系统中存在着中心化、交易信息和权限信息不透明的问题，利用区块链技术的去中心化、公开透明等优点，提出了一个基于区块链的数字权限保护系统。该系统使用星际文件系统（IPFS）存储加密的数字内容，通过智能合约完成权限交易和自动发放许可证，利用区块链记录权限交易信息和许可证信息。解决了传统数字权限保护系统中集中式内容服务器造成的单点故障问题，实现了无需任何集中服务器的许可证发放功能和权限交易功能，同时保证了信息的透明与可信。安全性和性能分析表明，该系统是安全可行的；仿真实验结果表明，该系统能够以较低的开销实现数字内容的权限保护。

关键词: 区块链, 智能合约, 星际文件系统（IPFS）, 以太坊, 数字权限管理