Research And Implementation Of Proxy Re-encryption

Proxy re-encryption is defined as client generates mandatary's Proxy re-encryption key,then sent the proxy re-encryption key to agent,thus agent u ses the proxy re-encryption key to convert the public key into the ciphertext of consignor.Proxy re-encryption is widely used in many situations,such as distributed file system,mail forwarding,secure cloud storage and digital cop yright protection etc.In this paper,two aspects are studied: the paper puts for ward an improved scheme for proxy re-encryption.Firstly,we propose an i mproved proxy re-encryption scheme with keyword search by repairing a tra pdoor in the proxy re-encryption scheme with keyword search.The improve d scheme has a trapdoor which can be transmitted in the open channel,and it is proved to be safe under the standard model;Secondly,we propose a simp lified and secure identity-based one-way proxy re-encryption scheme based on the analysis of Lou et al,which found that the original scheme was redun dant.Thus,the parameters simplified in the original scheme has the same se curity as the original scheme,and completely safe under the standard model.For its parameters are shorter,it is more efficient than the original scheme.