An Adaptive Secure Identity-Based Signcryption With Equality Test for High-Speed Railway Train–Ground Communication

The integration and fusion of more advanced emerging information technology and high-speed rail technology not only promotes the overall improvement of high-speed rail intelligence and facilitates people's modern life, but also puts forward higher requirements for the reliability of the data transmitted under high mobility scenarios. As a result, the huge amount of sensitive data has become one of the primary targets of illegal hackers. To address these challenging obstacles, we construct an identity-based signing scheme with the function of equality test. This scheme not only ensures the integrity, confidentiality, and authenticity of messages, but also allows the cloud server to execute an equality test on two signcryptexts signed by the same or different public keys to determine whether they contain the same plaintext, which can be used to categorize and manage signed messages transmitted by a large number of vehicles in the high-speed rail vehicle-to-ground communication system. More importantly, the proposed IBSC-ET scheme is shown to achieve adaptive security under the q-Modified Decisional Bilinear Diffie-Hellman Inversion (q-MDBDHI) assumption in the standard model. Finally, the practicability and efficacy of the proposed scheme are demonstrated through comprehensive performance analysis and comparative experimental evaluations.