BlockChain- Anchored Unified Identity Framework for Secure Electric Vehicle Charging Authentication

Electric vehicle charging infrastructure depends on two authentication paradigms with significant weaknesses. Autocharge, defined under DIN SPEC 70121, identifies vehicles by their unprotected Media Access Control (MAC) address with no cryptographic verification. Plug and Charge under ISO 15118 adds cryptographic authentication but relies on a centralized Vehicle-to-Grid Public Key Infrastructure (V2G-PKI) that creates single points of failure and multi-hour certificate revocation windows. These weaknesses are not theoretical: CVE-2025-12357 demonstrated man-in-the-middle interception of Signal Level Attenuation Characterization (SLAC) exchanges, and field studies have documented Transport Layer Security (TLS) silent downgrades in over 30 commercial vehicles. This paper describes a blockchain-anchored framework that brings both sets of existing solutions under a single decentralized trust layer built on a permissioned Hyperledger Fabric consortium of Original Equipment Manufacturers, Charge Point Operators, and e-Mobility Service Providers. A compact Elliptic Curve Digital Signature Algorithm (ECDSA) token with rotating pseudonyms handles vehicle authentication, charger side caching enables sub-millisecond verification for known vehicles and credential revocation propagates through blockchain event subscriptions rather than periodic certificate list refreshes. A calibrated Python simulation with real ECDSA operations yields a median cache-hit latency of 81 microseconds on a warm cache (76 microseconds in the city case). Under realistic city deployment conditions with 85 percent local traffic, that median holds while outperforming Autocharge by 375 times and PnC with Online Certificate Status Protocol by 3,700 times. Highway and rural chargers starting with empty caches see median latency around 10 milliseconds, still 3 times faster than Autocharge and 30 times faster than PnC with OCSP. Revocation reaches every consortium peer within one block-commit cycle, measured at 2.04 s worst-case on a live multi-node Hyperledger Fabric network. All tested scenarios remain within ISO 15118 Session Discovery Protocol timing budgets.