The Research Of Certificateless Signcryption Scheme And Its Applications

With the development of network technology, the information security becomes the important part of people survival and development in information era. Information security problem has gradually become a national strategic issues. In cryptography, the signature and encryption technology is the most direct and effective method to solve the information security problem. Compared with the traditional digital signature, signcryption technology can complete the encryption and signature at the same time, and reduce the computational costs and communication. So signcryption technology is one of more ideal method to realize the authentication and encryption.This paper mainly studies certificateless signcryption scheme. By studies certificateless signcryption of forefathers, we found the scheme exist a defect which is the user’s public key replaced under the attacker of type I. In view of the defect, we put forward an improved certificateless signcryption scheme based on bilinear pairings. The new scheme adds a partially public key on the basis of the original scheme. Namely the user’s public key is made up of two parts, one part of it is generated by the users themselves, and another part is generated by the Key Generation Center(KGC). And we make use of a secure hash function to generate partially private key of the user, then an attacker can’t make use of substitution user’s public key to eliminate the effect of hash function, so the new scheme can resist the public key substitution attack.In the random oracle machine model, it proved that the new scheme has confidentiality based on the decisional bilinear Diffie-Hellman proplem(DBDH) difficulty assumption; And based on computational Diffie-Hellman problem(CDH) difficulty assumption the new scheme is existentially unforgeable.In the process of vehicle automated driving through receiving and sending information such as road conditions, light et al to realize route. But in the process of information exchange, there is information was leaked, tamper with the threat, it will bring a deadly threat to traffic safety. For all this, we according to the communication of vehicle automated driving system model, and proposed the communication model between vehicle to vehicle(V2V) based on the algorithm of the new signcryption scheme. This model mainly divided into four stages: system initialization and vehicle registration, authentication and key agreement of the vehicle, message sign and send, decrypt validation phase. According to the algorithm, we will signcrypt the each vehicle will send messages(including the surrounding traffic, road traffic conditions and traffic signs, etc.), and to ensure that the vehicles passed between information integrity, confidentiality, accuracy.