A certificateless proxy re-signcryption scheme is advanced by combining certificateless cryptosystem with signcryption.In this scheme

the transparent conversion from one signcryption to another is achieved by utilizing a semi-trusted proxy.Compared with the other similar schemes

this scheme realizes the complete conversion of signcryption.Generally

after the signcryption under the private key of Alice and the public key of Bob is converted

it can only be de-signcryted by using the identity information of Alice and the private key of Daddy.However

in the scheme advanced in this paper

not only can the identity information of Charlie and the private key of Daddy de-signcrypt the converted signcryption under the private key of Alice and the public key of Bob

but also the verification of signcrytion does not involve the direct participation of plaintext.Based on the GBDH problem

it can be proved that this scheme can resist the first kind of attacks in certificateless proxy re-signcryption under the Random Oracle Model.