Abstract:

Proxy cryptosystem, first proposed by Mambo and Okamoto, allows the original decryptor to delegate his decrypting capability to the proxies. The proxy-protected anonymous proxy encryption, proposed by Zhang, is a new proxy cryptosystem, in which only the proxy decryptor can decrypt the ciphertexts for the original decryptor. Certicate-based public key cryptography was introduced to simplify key management procedures of the conventional public key cryptography and overcome the key escrow problem in the identity-based public key cryptography. It has attracted many researchers to propose a large number of schemes. In this paper, we study the relationship between the proxy-protected anonymous proxy encryption and the certificated-based encryption. We propose a generic construction for proxy-protected anonymous proxy encryption and prove its security. Using the proposed method, any secure certificated-based encryption scheme can be transformed into a secure proxy-protected anonymous proxy encryption. As an example, we give a secure proxy-protected anonymous proxy encryption in the stand model obtained by the proposed method.