【摘要】 在密文策略的属性基加密方案中,用户的私钥与属性集合关联,密文与访问策略关联,当且仅当用户私钥中所包含的属性满足嵌入在密文中的访问策略时,用户方能成功解密该密文。在现有方案的解密过程中,访问策略连同密文被发送给解密者,这意味着加密者的隐私被泄露。为解决该问题,提出了具有隐藏访问策略的密文策略属性基加密方案,以保护加密者的隐私;并基于DBDH假设,证明了该方案在标准模型中是选择明文安全的。更多还原

【Abstract】 In ciphertext-policy attribute-based encryption(CP-ABE)scheme,a user’s secret key is associated with a set of attributes,and the ciphertext is associated with an access policy.The user can decrypt the ciphertext if and only if the attribute set embedded in his secret key satisfies the access policy specified in the ciphertext.In the present schemes,the access policy is sent to the decryptor along with the ciphertext,which means that the privacy of the encryptor is revealed.In order to solve such problem,we proposed a CP-ABE scheme with anonymous access policy,which is able to preserve the privacy of the encryptor.Our new scheme is proved to be selectively secure against chosen-plaintext attack under DBDH assumption in the standard model.更多还原