EmuLab of Security Credential Management System (SCMS) for Vehicular Communications

Abstract

The Security Credential Management System (SCMS), currently being developed in the United States, implements Vehicular Public Key Infrastructure (V-PKI). Besides conventional PKI function for security, SCMS features privacy protection mechanisms. SCMS will become the largest PKI in the word and considers efficiency in its design. However, SCMS itself becomes the target of security attacks, leading to safety-of-life risk in connected and autonomous vehicles. Securing SCMS will undergo battles as new threats emerge, which needs to update defense such as misbehavior detection. Some challenges remain open, like efficient distribution of certificate revocation lists. In addition, certain solutions, like butterfly key expansion, do not withstand post-quantum cryptanalysis. This paper presents an SCMS Emulation Lab (EmuLab) designed at the University of Massachusetts Dartmouth. EmuLab facilitates research to strengthen SCMS security with a functional SCMS framework. Two sets of experiments on EmuLab demonstrate how pseudonym certificates work and how SCMS self-heals when a root certificate authority is compromised. Emulation supplements field tests for proof-of-concept at a large scale with no danger to life. Its high fidelity provides more realistic results than that offered by simulation on experimenting new defense mechanics. The emulated system is readily deployable to pilot programs for real world operation. EmuLab also serves to educate and train SCMS operators and administrators.