A Vehicular DAA Scheme for Unlinkable ECDSA Pseudonyms in V2X
Christopher Hicks, Flavio D. Garcia
Abstract
Vehicle-to-everything (V2X) communication is a broadcast messaging system intended to improve the efficiency and safety of connected and autonomous vehicles. In this paper we present a new V2X architecture and key management solution that reconciles the strong privacy guarantees of Direct Anonymous Attestation (DAA) with the efficiency, low-latency and accountability that is required for V2X. In contrast with the leading V2X standards, and uniquely in the literature, we prevent long-term vehicle pseudonym tracking despite dishonest and colluding certificate authorities and whilst retaining centralised authority over revocation. Our Vehicular DAA (VDAA) scheme includes a novel construction that optimally limits Sybil attacks by restricting each vehicle to one anonymous pseudonym-request per epoch. We present a new security model for VDAA and show that we can reduce the unforgeability and unlinkability of our Elliptic Curve Digital Signature Algorithm (ECDSA) broadcast messages to the security of the underlying DAA scheme.