提出基于格和分层身份结构的广播加密方案.该方案采用格表示用户身份信息,通过格和子格的结构关系表示分层结构,以格的短基表示用户的私钥,利用格基生成算法迭代生成每层格的短基,基于格中错误学习难题设计加、解密算法.理论分析证明,对于非授权用户,该方案在适应性选择密文攻击下具有不可区分安全性,对于授权用户,在选择密文攻击下具有前向安全性,与基于双线性对的广播加密方案相比计算速度更快.%This paper presents a broadcast encryption scheme based on lattice and hierarchical identity, whose encryption and decryption algorithms are based on Learning with Error(LWE) hard problem. Each user's identity is associated with a lattice matrix, and the relationship between the lattice and its sub-lattice can easily represent the hierarchical identity construction. Short basis of a lattice is treated as a private key of a user, and based on the lattice delegation algorithm, the private key for each level's user can be derived. Theory analysis proves that the scheme is Indistinguishable-Chosen Ciphertext Attack 2(IND-CCA2) secure against the attacks by outsider users and Forward Safe-Chosen Ciphertext Attack (FS-CCA) secure against the attacks by authorized receivers. Compared with the broadcast encryption scheme based on the bilinear mapping, it is more efficient in the encryption and decryption.
展开▼
