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Interoperability Strategies

Introduction to Trust Bridges

Trust bridges are mechanisms that enable the secure sharing of information between two independent trust domains. They can facilitate sharing between trust domains with differing security and operating policies, and support bridging between trust domains that rely on different frameworks, such as X.509 and IEEE 1609.2.

The concept of a trust bridge is to enable secure sharing of information across independent trust domains. A trust bridge ensures that data integrity, confidentiality, and authenticity are preserved throughout the transfer, even when bridging involves proprietary systems.

What a Trust Bridge Can Support

  1. Bridges Security Frameworks
    Trust bridges allow secure communication between trust domains that rely on disparate security frameworks.

  2. A trust bridge can validate message content using one framework and re-sign the content using a different framework.

  3. Facilitate Secure Interoperability: Trust bridges can act as intermediaries between different policy domains, ensuring secure and consistent communication.

  4. End-to-End Security: Trust bridges support end-to-end authentication by ensuring messages remain tamper-proof and verifiable from source to destination.

  5. Support Interactions with Proprietary Systems: Trust bridges enable integration of proprietary systems by securely forwarding communications from a public domain to a proprietary domain.

Attributes of a Trust Bridge

A trust bridge should be designed and developed to mitigate the cybersecurity risks faced by all domains it interacts with. Without these safeguards, the trust bridge risks becoming a weak link in the system's security. Key attributes of a trust bridge include:

  1. Tamper Resistance: Trust bridges should be resistant to both physical and electronic tampering.

  2. An ITS Station configured with an X.509 certificate may need to communicate with a vehicle configured with IEEE Std. 1609.2 certificates.

  3. End-to-End Authentication Preservation: Trust bridges must maintain message authenticity across bridged domains, ensuring data integrity and trust.

  4. Auditable: Trust bridges should maintain detailed event logs for tracking and auditing communication events.