A2A Authentication & Security — Secure Cross-Agent Communication

I will implement A2A-compliant authentication and security for your cross-agent communication — covering OAuth 2.0 or API key authentication schemes as declared in agent cards, mTLS for transport security, request signing for message integrity, and an authorisation layer ensuring agents only receive task requests within their declared scope. Cross-agent communication security requires careful implementation because agents operating with real-world tool access (email sending, database writing, financial transactions) create significant damage potential if an agent accepts tasks from unauthorised sources — a properly implemented A2A security layer ensures only authenticated, authorised agents can delegate tasks.

The implementation covers authentication scheme implementation per the A2A card declaration, mTLS configuration for transport security, request signature generation and verification, authorisation scope enforcement, and security audit logging for all cross-agent interactions.