Unanswered authentication and authorization issues in Agent-to-Agent (A2A) communication

Develop standardized authentication and authorization mechanisms for the Agent-to-Agent Protocol (A2A) that go beyond simple agent access and explicitly enforce scope attenuation and resource-use restrictions for downstream agents in multi-agent workflows.

Background

The paper describes A2A as a protocol for inter-agent communication that currently outlines how authentication should be performed but leaves many questions unanswered, especially regarding authorization semantics in multi-agent chains.

The authors emphasize additional complexities arising when authorization must extend beyond mere access to another agent and into setting and enforcing restrictions on scope and resource use for downstream agents, highlighting the need for standardized mechanisms to maintain least privilege in recursive delegation scenarios.