Vehicle Access Management Using Blockchain-Based Temporary Credential Scheme

Vehicle access to restricted and government-controlled sites requires verification of persistent vehicle and driver identity together with temporary authorization conditions. This study presents a blockchain-supported temporary credential scheme that separates persistent identity references from request-specific access conditions. A QR code is used as the presentation medium for a custom signed credential containing vehicle and driver identifiers, plate number, validity information, geofence parameters, and a nonce, while the blockchain maintains the corresponding credential hash, nonce, usage state, and revocation state. The scheme was evaluated through a bonded-zone case study using a public reference implementation and explicit trust assumptions. Six implemented conditions were tested: credential expiration, replay after successful use, out-of-geofence presentation, revocation, tampering of five signed payload fields, and cryptographic-key replacement while retaining the same prototype identifier. Across 55 recorded verification outcomes, all expired, replayed, out-of-geofence, revoked, and tampered credentials were rejected as expected. In the key-replacement experiment, all credentials generated with the previous key were rejected, whereas all newly generated credentials using the replacement key were accepted. Configuration-specific baseline experiments were also performed using an HS256 JWT implementation with centralized replay state and a blockchain implementation using ordinary vehicle and driver identifiers. The results demonstrate correct enforcement of the implemented credential-verification and blockchain-state rules under controlled prototype conditions, rather than comprehensive resistance to all real-world threats.