A Secure and Efficient Pairing-Free Certificateless Aggregate Signcryption Scheme for V2G Networks

The vehicle-to-grid (V2G) network is an infrastructure for electric vehicles (EVs) to be charged and discharged. As EVs are increasingly connected to V2G networks, V2G networks are facing serious data security problems. Attackers may eavesdrop on, tamper with, and forge the electricity transaction data, which will seriously damage the security of the transmitted data and affect the V2G network's normal operation. To ensure secure and efficient transmission of electricity transaction data, a pairing-free certificateless agregate signcryption (PCAS) scheme is proposed in this article. The PCAS scheme is theoretically proven to provide confidentiality, unforgeability, etc. On the premise of ensuring data security, time-consuming pairing operation is avoided in the PCAS scheme, the certificateless mechanism is used to avoid certificate management and key escrow issues, the verification time of ciphertext is reduced by using aggregate signcryption, and the special random number processing method is adopted to reduce the complexity of signcryption process. The scheme is more efficient by adopting these measures. The performance analysis results demonstrate that the PCAS scheme takes less computing time than compared schemes. When massive EVs are charged and discharged through V2G networks, the data are transmitted more securely and efficiently by using the PCAS scheme.