ISO/SAE 21434: Proving Software Security, Not Just Declaring It

ISO/SAE 21434 defines a lifecycle approach to managing automotive cybersecurity risk from concept through decommissioning. For software teams, compliance means demonstrating that security is built into the codebase, not added after the fact.

This white paper takes a technical look at what that requires in practice, where vulnerabilities originate, why they persist, and how to eliminate them with mathematically rigorous methods.

Key topics:

• Expanding attack surfaces driven by V2X, OTA updates, and connectivity
• Structural weaknesses in ECUs and in-vehicle communication networks
• Undefined behavior in C/C++ as a critical, often invisible risk
• Why testing and traditional static analysis cannot prove software is free of critical vulnerabilities
• How formal methods eliminate entire classes of vulnerabilities and support ISO/SAE 21434 compliance

Mitsubishi Electric Uses Formal Methods to Meet ISO/SAE 21434 Assurance Requirements. https://www.trust-in-soft.com/success-stories/automotive/mitsubishi-electric-rd-centre-europe