Thesis Defence: From Blockchain Trust Models to Native Security Protocols: Enhancements of the A2A Communication Framework
November 27 at 9:30 am - 1:30 pm
Weixiao Wang, supervised by Dr. Chen Feng, will defend their thesis titled “From Blockchain Trust Models to Native Security Protocols: Enhancements of the A2A Communication Framework” in partial fulfillment of the requirements for the degree of Master of Applied Science in Electrical Engineering.
An abstract for Weixiao Wang’s thesis is included below.
Defences are open to all members of the campus community as well as the general public. Please email chen.feng@ubc.ca to receive the Zoom link for this defence.
Abstract
Agent communication protocols are rapidly emerging as the core infrastructure for multi-agent systems. Still, existing protocols often prioritize either usability (e.g., A2A, MCP, ACP) or encryption security (e.g., ANP, IoA), making it challenging to balance both. This paper proposes an enhanced design based on the A2A protocol, introducing message-level default security mechanisms while maintaining its lightweight advantages. The core improvements include: signature verification based on decentralized identity, random number replay prevention, chained hashing to ensure message order, cumulative hashing to guarantee historical integrity, and an efficient interception mechanism through a `quick failure’ verification process. I have constructed a reproducible prototype system and validated the effectiveness of the design through four types of typical attack tests (tampering, replay, chain breaking, and historical destruction).
The results show that the enhanced scheme can instantly reject tampered and replayed messages and accurately detect sequence or historical anomalies within a sliding window. Further comparative analysis reveals that among seven mainstream threats (impersonation registration, message replay, context tampering, registration deception, credential theft, token replay, and denial of service), only the enhanced A2A can effectively defend against all threats at the message layer, while existing protocols have gaps. This study provides A2A with an evolution path that balances simplicity and security, laying the foundation for achieving auditable and scalable secure communication in complex cross-domain and multi-organization environments in the future.
