Research On The Application Of Public Key Cryptography Algorithm For Vehicular Communication

The Internet of Vehicles(IoV)can improve the intelligence of automobiles,enhance traffic efficiency,improve driving experience,and provide users with intelligent,safe,and efficient integrated services.To meet the requirements of safety and privacy in the IoV,the US Department of Transportation has developed the Security Credential Management System(SCMS).SCMS provides secure and reliable communication and interaction for entities such as vehicles in the IoV through digital certificates and identity authentication.Vehicle-to-vehicle(V2V)communication is the most important communication scenario in the IoV.In the V2V communication scenario,vehicles communicate with other vehicles by broadcasting Basic Safety Message(BSM).To prevent attackers from forging messages,the sender is required to use a pseudonym certificate to create a digital signature for each BSM,and the receiver needs to verify the signature of the BSM.To obtain a pseudonym certificate,a vehicle need to send a request to the Registration Authority(RA).To ensure the authenticity and confidentiality of the request,the vehicle is required to sign it with a registration certificate and encrypt it with the RA’s certificate.Relevant literature has pointed out that a vehicle will receive up to more than one thousand BSM to be verified within one second,and the verification delay cannot exceed one hundred milliseconds in the V2V communication scenario,which is difficult to achieve with the existing in-vehicle equipment.Therefore,improving the verification efficiency of BSM is crucial.When signing with a registration certificate,the private key is only controlled by the vehicle,and once leaked,an attacker can impersonate a legitimate vehicle and sign malicious messages,disrupting the security of communication in the IoV.Therefore,enhancing the security of the private key is also crucial.If there are vulnerabilities in the RA’s decryption function,attackers can exploit them to launch attacks when receiving pseudonym certificate request.Therefore,ensuring the secure implementation of encryption and decryption algorithms are of important practical significance.This thesis investigates the efficiency of BSM verification and the enhancement of cryptography algorithm security in IoV communication,including the following three aspects:Regarding the efficiency of BSM verification,this thesis proposes a signature aggregation verification scheme based on ECQV implicit certificate and Schnorr signature,which can significantly reduce the computational cost of signature verification.When the verifying vehicle receives n BSM,it can perform one aggregated verification,which significantly reduces the computational cost compared to one-by-one verification.Furthermore,in the case of a BSM with wrong signature,a fast verification error correction scheme is proposed.Based on the different pre-computation configurations of the verifying vehicle,the optimal number of groups and computational costs of the scheme are analyzed separately.The results show that the computational cost of the fast verification error dection scheme is significantly better than that of the one-by-one verification error dection method.Regarding the private key security of digital signature algorithms,this thesis proposes a two-party threshold framework for the SM2 signature algorithm.The framework provides a correct and safe calculation process of 2-party threshold schemes for SM2 digital signature and can introduce the signature random number that can be constructed variously.Using the proposed framework,multiple instantiations of the SM2 digital signature algorithm are completed,including 23 known two-party threshold calculation schemes and several new schemes.Regarding the secure implementation issue of encryption and decryption algorithms,this thesis analyzes a buffer overflow vulnerability in the SM2 decryption interface that has been publicly disclosed in OpenSSL.The analysis shows that the vulnerability is caused by inconsistent buffer length calculation and the calculation of the length of the plaintext to be filled.An attacker can quickly enumerate the calculation to obtain a suitable elliptic curve point and construct a suitable ciphertext to launch a buffer overflow attack.Moreover,the attacker can use the same elliptic curve point to launch buffer overflow attacks on different public and private key pairs of SM2 decryption parties.