Certificateless Proxy Signcryption Using Cyclic Multiplication Groups

Proxy signcryption is that the proxy signcrypter obtains the delegate authorization from the original signcrypter, and then signcrypts the specified message on behalf of the original signcrypter. In this paper, the author constructs a novel certificateless proxy signcryption scheme based on three cyclic multiplication groups and its security bases on the intractability of the co-bilinear Diffie-Hellman (co-BDH) and co-computational Diffie-Hellman (co-CDH) problems. Our certificateless proxy signcryption scheme is very appropriate for applications in electric commerce and electric government.