Cryptanalysis of a Certificateless Proxy Re-encryption Scheme

Recently, Sur et al. introduced a new primitive named certificateless proxy re-encryption, which enjoys the advantages of certificateless public key cryptography while providing the functionalities of proxy re-encryption. They further proposed a certificateless proxy re-encryption scheme, and claimed that their scheme is secure against chosen-cipher text attacks in the random oracle model. However, by giving a concrete attack, in this paper we indicate that their PRE scheme is not secure against chosen-cipher text attacks.