针对当前云环境下属性基访问控制机制中采用中央授权中心带来的安全性问题,提出了分散多机构属性基加密DMA-ABE方案.该方案采用多个授权中心负责用户密钥的分发,无需中央授权中心的协调;支持任意的线性秘密共享方案访问结构,访问策略灵活;采用代理重加密进行属性的即时撤销和授权,支持高效、灵活、细粒度的访问控制.安全性分析证明该方案达到选择明文攻击安全. In order to solve the security problem brought by central authorization center in attribute-based access control mechanism in current cloud environment, this paper proposes a decentralized multi-agent attribute-based encryption DMA-ABE scheme which uses multiple authorization centers to distribute user keys without the need of Central authorization center coordination; support arbitrary linear secret sharing scheme access structure, flexible access strategy; using proxy re-encryption for attribute immediate withdrawal and authorization, support efficient, flexible and fine-grained access control.Security analysis shows that the program to achieve Choose plaintext attack security.