The Design Of The Two Certificateless Signcryption Schemes

With the wide use of computer network,the confidentiality and authentication of information,the security and protection of network have been paid more and more attention by all circles in the society.Cryptography is a particularly critical technology in information security and plays a very vital role in information security.Signcryption is a relatively novel primitive in cryptography.It is lower in computation and communication costs than the traditional ”signature first after Encryption”.The certificateless signcryption scheme combines the advantages of a certificateless cryptosystem and a signcryption,not only to complete the signature and encryption of the message simultaneously in the same logical step at a lower communication cost,but also to avoid the storage problem of the public key certificate of the public key infrastructure and key escrow problem of identity-based cryptosystem.Because of the above reasons,the certificateless signcryption has been paid much attention by the academic and industrial circles,and has been widely used in various fields such as wireless self-organizing network and Internet of things,therefore it has become a hot topic in current research.The uniqueness of the ring signatures is that anyone can verify that the signature is done by a member of the ring,but cannot confirm who the real signer is.The multi-receiver cryptosystem can send one ciphertext to multiple receivers,which is more efficient than encrypting the same message and then sending different ciphertexts to the corresponding receiver.In this paper,the certificateless signcryption scheme is combined with the ring signature or multi-receiver cryptosystem cryptosystem respectively,and the signcryption scheme with special properties is designed,and the following work is completed:1.A new certificateless multi-receiver signcryption scheme is designed,and the new scheme is proved to satisfy the indistinguishable and unforgeable in the random oracle mode.And the correctness of the new scheme is analyzed.Compared with other certificateless multi-receiver certificateless schemes,it has proved that the new scheme has lower computation.2.Combining the basic idea of certificateless signcryption with the ring signature,a new certificateless ring signcryption scheme is designed.In the random oracle mode,the security of the new scheme was proved.Compared with other certificateless ring signcryption schemes,it is verified that the new scheme has lower computation.