关键词: 云计算, 云安全, 基于属性的加密, 重加密, 密钥管理

Abstract: The security problem of the data stored in the cloud is a challenge for cloud computing. Encryption is the main method to solve the problem of data storage security in cloud computing. The confidentiality issue of the encryption is the key management. The attribute-based encryption and re-encryption scheme in cloud computing was proposed. It combined attribute-based encryption and re-encryption technology. The cloud server could re-encrypt for different users, and re-encrypt for a group of users at a time. Thereby the scheme reduced the number of re-encryption keys. The data owner could generate and send the keys of re-encryption for a group of users and the data requester could use the key corresponding to the attribute set to decrypt the data of several data owners, which reduced the amount of keys’ transmission. The scheme reduced the difficulty of key management and improved the efficiency of the scheme. In the end, the security and efficiency of the scheme were discussed.

Key words: cloud computing, cloud security, attribute-based encryption, re-encryption, key management