关键词: 云存储安全, 公钥密码, 代理重加密, 数据机密性, 访问控制

Abstract:

Concerning the data's confidentiality when being stored in the untrusted cloud storage, a new encryption algorithm based on the Proxy Re-Encryption (PRE) was proposed, and applied in the access control scheme for the cloud storage. The scheme had partial ciphertexts stored in the cloud storage for sharing, and the others sent to users directly. It was proven that the scheme can ensure the confidentiality of the sensitive data stored in the cloud storage under the third untrusted open environment. By contrast, the experimental results show the transmission of ciphertexts can be controlled by the sender. The scheme used the properties of the proxy re-encryption. The number of ciphertexts' operation and storage did not increase linearly with the increase of the users. It decreased the data computation cost, interactive cost, and the space of the data storage effectively. The scheme achieves sharing securely and efficiently when the sensitive data is stored in the cloud.

Key words: cloud storage security, Public Key Cryptography(PKC), Proxy Re-encryption(PRE), data confidentiality, access control