RSA-Based Anonymous Certificate for Security Credential Management System

Over the past few years, the U.S. Department of Transportation has embraced the Institute of Electrical and Electronics Engineers (IEEE) 1609 series as the standard for establishing the Security Credential Management System (SCMS) in Vehicle-to-Everything (V2X) communication across the United States. Elliptic curve cryptography (ECC) has been adopted for a butterfly key expansion (BKE) method in the IEEE 1609.2.1 standard. This study proposes a RSA-based key expansion method for anonymous certificate with higher efficiency in SCMS. This paper presents mathematical principles to demonstrate the feasibility of encryption/decryption, car privacy, and method efficiency. In practical settings, our proposed method significantly improves the efficiency of the key expansion method specified in the IEEE 1609.2.1-2022 standard by thousands of times, all while maintaining the same level of security strength.