Research On Online/Offline Signcryption Scheme In Heterogeneous Cryptography

Currently,data transmission and processing requires to be done in the public network as the rapid development of information and digitization.Therefore,people have higher demand for data security.Cryptography is the core of data security,which provides security services such as confidentiality,integrity and non-repudiation.Signcryption simultaneously fulfils the functions of digital signature and public key encryption to achieve the confidentiality and unforgeability of data,which is the key technology of cryptography.The cost of communication of signcryption is lower than traditional signature-then-encryption method,which has higher practical value.Most of the existing signcryption schemes are based on the same cryptography environment,which use PKI technology or identity-based cryptography.In order to solve the security problem with heterogeneous communication systems,the heterogeneous signcryption is studied.However,the existing heterogeneous signcryption schemes use the same system parameters in different cryptography,which cannot satisfy the practical requirements.At the same time,because the cost of ordinary signcryption schemes is high,the schemes cannot satisfy the mobiles which the computing power and storage capacity is limited.The researchers combine online/offline technology with signcryption to propose an online/offline signcryption schemes.Therefore,it is necessary to design online/offline heterogeneous signcryption scheme which is suitable for mobile devices in heterogeneous network environment.In order to ensure the confidentiality and authentication of data transmission and processing in heterogeneous network environment,the main researches of this paper are as follows:(1)This paper constructs the IDPKC-to-CLPKC heterogeneous signcryption scheme.Since both IDPKC and CLPKC are avoid the problem with certificates management in the TPKC,this paper constructs from identity-based public key cryptography to certificateless public key cryptography heterogeneous signcryption scheme with the communication environment which the sender is IDPKC and the receiver is CLPKC.Besides,it has the different system parameters for the IDPKC and the CLPKC.Based on the gap bilinear Diffie-Hellman difficult problem,computational Diffie-Hellman difficult problem and q-strong Diffie-Hellman difficult problem,we prove that the scheme satisfies the confidentiality and unforgeability of the heterogeneous cryptography under the random oracle model.At the same time,the scheme has anonymity which the adversary cannot get the sender and receiver's identity by the ciphertext,so that the identity information is protected.Moreover,through analyzing the simulation experiment,the proposed scheme performance is better than the existing schemes.(2)This paper constructs the IDPKC-to-CLPKC online/offline heterogeneous signcryption scheme.Based on IDPKC-to-CLPKC heterogeneous signcryption,the IDPKC-to-CLPKC online/offline heterogeneous signcryption scheme is proposed by combining with online/offline technology.The scheme splits the procedure of signcryption into two phases: offline phase and online phase.In the offline phase,most heavy computations are carried out without the message and the receiver's identity.In the online phase,only light computations are done when the message and the receiver's identity are known.Besides,it has the different system parameters of the IDPKC and the CLPKC.Based on the q-bilinear inverse Diffie-Hellman difficult problem,the modified bilinear inverse Diffie-Hellman difficult problem and the q-strong Diffie-Hellman difficult problem,the scheme is proved to satisfy the confidentiality and unforgeability of the heterogeneous cryptography under the random oracle model.Moreover,through analyzing the simulation experiment,the proposed scheme is more efficient and suitable for the heterogeneous communication systems with the limit of computation power and storage capacity.