SALT-V: Lightweight Authentication for 5G V2X Broadcasting

2025-11-14

AI Summary

V2X communication faces a fundamental trade-off between security and real-time performance in authentication: public-key schemes (e.g., ECDSA) incur ~2 ms latency—insufficient for collision avoidance—while symmetric schemes (e.g., TESLA) achieve microsecond-scale verification but suffer from 20–100 ms key disclosure delays. To resolve this, we propose a hierarchical hybrid authentication framework featuring an ephemeral session tag (EST)-based whitelist mechanism and Bloom-filter-accelerated revocation checking, enabling sub-millisecond revocation validation with 95% of messages verifiable instantly. The framework anchors trust via ECDSA signatures on 10% of beacon frames and delegates lightweight, batched GMAC authentication to the remaining 90% of data frames. Evaluation shows an average computation latency of 0.035 ms, end-to-end delay of 1 ms, overhead of 41 bytes, and linear scalability to 2,000 nodes—fully meeting 5G NR-V2X real-time security requirements.

Technology Category

• Multiagent Systems: Agent Communication
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Application Domains: Security

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures
• Responsible Web: Data and user privacy-enhancing technologies for the Web

Abstract

Vehicle-to-Everything (V2X) communication faces a critical authentication dilemma: traditional public-key schemes like ECDSA provide strong security but impose 2 ms verification delays unsuitable for collision avoidance, while symmetric approaches like TESLA achieve microsecond-level efficiency at the cost of 20-100 ms key disclosure latency. Neither meets 5G New Radio (NR)-V2X's stringent requirements for both immediate authentication and computational efficiency. This paper presents SALT-V, a novel hybrid authentication framework that reconciles this fundamental trade-off through intelligent protocol stratification. SALT-V employs ECDSA signatures for 10% of traffic (BOOT frames) to establish sender trust, then leverages this trust anchor to authenticate 90% of messages (DATA frames) using lightweight GMAC operations. The core innovation - an Ephemeral Session Tag (EST) whitelist mechanism - enables 95% of messages to achieve immediate verification without waiting for key disclosure, while Bloom filter integration provides O(1) revocation checking in 1 us. Comprehensive evaluation demonstrates that SALT-V achieves 0.035 ms average computation time (57x faster than pure ECDSA), 1 ms end-to-end latency, 41-byte overhead, and linear scalability to 2000 vehicles, making it the first practical solution to satisfy all safety-critical requirements for real-time V2X deployment.

Problem

• Resolves authentication latency-efficiency trade-off in 5G V2X communication
• Enables immediate message verification without key disclosure delays
• Achieves microsecond-level authentication for safety-critical vehicle applications

Innovation

• Hybrid authentication framework combining ECDSA and GMAC
• Ephemeral Session Tag whitelist for immediate verification
• Bloom filter integration for microsecond revocation checking