【摘要】 一个理想的代理重加密方案通常具有单向性、非交互性、可重复性、可控性和可验证性,然而目前的方案普遍只满足其中的2个或3个,在一定程度上降低了实用性。为此,提出了一种支持5种特性的密文策略基于属性代理重加密(CP-ABPRE)方案。在所提方案中,云代理服务器只能利用重加密密钥重加密委托者指定的密文,抵御了满足重加密共享策略的用户与代理之间的共谋攻击;将多数加解密工作外包给云服务器,减轻了用户客户端的计算负担。安全分析表明,所提方案能抵御针对性选择明文攻击。更多还原

【Abstract】 A ideal proxy re-encryption scheme has five features, such as one-way encryption, non-interaction, repeatability, controllability and verifiability. The existing schemes, however, have only two or three of the five features, which reduces the utility of them to some extent. For this, a new ciphertext-policy attribute-based proxy re-encryption(CP-ABPRE) scheme with the above five features was proposed. In the proposed scheme, the cloud proxy server could only re-encrypt the ciphertext specified by the delegator by using the re-encryption key, and resist the collusion attack between the user and the proxy satisfying the re-encryption sharing policy. Most of encryption and decryption were outsourced to cloud servers so that it reduced the computing burden on the user’s client. The security analysis show that the proposed scheme resists the selective chosen plaintext attack(SCPA).更多还原