Ciphertext-policy attribute-based proxy re-encryption via constrained PRFs

摘要

＜正＞Dear editor,To maintain the confidentiality of the sensitive data, users tend to encrypt their data under an associated access policy（or attributes） before outsourcing them to the cloud.In the traditional access control model via cryptographic approaches, e.g., ciphertext-policy attribute-based encryption（or CP-ABE）, users are allowed to formulate access policies and let the encrypted data associated with access policies. Only authenticated users, whose own attributes matching their formulated access policies, have the privilege to recover the ciphertext. However, once the access policies are formulated, the authorized user cannot update it unless the user downloads and re-encrypts the file under the new access policy. Hence, to achieve dynamic access control, the model of ciphertext-policy attribute-based proxy re-encryption（or CP-AB-PRE） is adopted by integrating the proxy re-encryption（or PRE）.