Efficient Heterogeneous Signcryption with Forward Privacy for Vehicular Platoon Communication

In the evolution of Intelligent Transportation Systems (ITS), autonomous vehicle platoon has emerged as a pivotal technology, where platoon followers periodically transmit critical information (such as speed and acceleration) to the platoon leader to maintain coordination and synchronization within the formation. Heterogeneous signcryption has garnered significant attention as a mean to ensure secure data transmission in environments characterized by diverse natures of vehicles. However, existing heterogeneous signcryption schemes fail to provide forward privacy and incur significant computational overhead during unsigncryption. To address these challenges, we propose an efficient heterogeneous signcryption scheme with forward privacy (HSCFP) for vehicular platoon communication. First, based on Elliptic Curve Cryptosystem (ECC), we introduce a heterogeneous signcryption framework that transitions data from Identity-based Cryptosystem (IBC) to Public Key Infrastructure (PKI), enabling seamless communication across cryptosystems. Next, we design an incremental update mechanism based on Updatable Public Key Encryption (UPKE) and Hashed EIGamal, ensuring the long-term security of historical communications. Additionally, we design a batch verification algorithm that significantly accelerates the unsigncryption process when dealing with multiple ciphertexts. Finally, we provide a rigorous security analysis of HSCFP under the random oracle model, and extensive experimental results demonstrate our scheme enhances unsign-cryption efficiency by over 60% compared to existing solutions.