Designated Verifier Signcryption Research And Its Application

The transmission of network data often requires encryption and digital signature technology.The purpose of this is to make it confidential,while also satisfying integrity,authentication and non-repudiation.Signcryption is a cryptographic protocol that enables both signing and encryption in a reasonable logical step.In order to enhance the privacy of the signer and improve the control of the signer's signature,the idea of designated verifier signature is proposed.In the designated verifier signature,the signer does not want anyone other than the designated recipient to believe the validity of the signature,so the verifier is designated in advance,and only the designated verifier can verify the validity of the signature.The verification process is signed.The recipient does not participate,at the same time,the recipient can also generate a signature transcript that is indistinguishable from the signature generated by the signer,so the recipient cannot allow any third party to believe that the signature was signed by the signer.This thesis combines the idea of the certificateless with the signcryption to achieve secure communication while ensuring the privacy of the signer.This thesis makes a corresponding study from the non-authorization of the signature authority and verification right of the PKI-based designated verifier signcryption and the designated verifier signcryption under the certificateless,which is embodied in the following aspects:1.Firstly,the development process,research background and related mathematical foundation of the designated verifier signature and signcryption are introduced in detail.2.Based on Sujata's designated verifier signcryption scheme,an improved designated verifier signcryption scheme is given.The scheme is based on the discrete logarithm problem.In this scheme,the secure transmission between the signer and the designated verifier can be realized without a secure channel.This scheme has been proven safe under adaptive selection of plaintext attacks.In addition,the scheme satisfies the non-authorization security requirement,and can prevent the ciphertext from being tampered with during the signcryption transmission process,and gives the correctness analysis and security proof of the scheme.Compared to Sujata's solution,our solution has advantages in terms of security and computational efficiency.3.Based on Zhou's certificateless signature scheme,combined with the idea of designated verifier signature and signcryption,a certificateless designated verifier signcryption scheme is constructed.This scheme is based on the discrete logarithm problem and meets the security requirements of designation verifier signcryption.This scheme does not use bilinear pairing operations,which preserves the high computational efficiency of the original scheme.4.Combined with the bitcoin transaction scenario on the blockchain,the system model and security model definition of the designated verifier's asset proof are given,and the designated verifier signcryption scheme proposed in this thesis is applied to the asset proof based on bitcoin exchange,greatly improved the transaction turnover ratio of the business.