Saved in:
Bibliographic Details
Main Authors: Zheng, Shenghan, Zhang, Qifan
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.23801
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914420368605184
author Zheng, Shenghan
Zhang, Qifan
author_facet Zheng, Shenghan
Zhang, Qifan
contents AI agent protocols -- including MCP, A2A, ANP, and ACP -- enable autonomous agents to discover capabilities, delegate tasks, and compose services across trust boundaries. Despite massive deployment (MCP alone has 97M+ monthly SDK downloads), no systematic security framework for these protocols exists. We present three contributions. First, the Agent Protocol Stack, a 6-layer architectural model that defines what a complete agent protocol must specify at each layer -- analogous to ITU-T X.800 for the OSI stack. Second, the Agent-Agnostic Security Model, 11 security principles formalized as TLA+ invariants, each tagged with a property taxonomy (spec-mandated, spec-recommended, aasm-hardening, aps-completeness) that distinguishes protocol non-conformance from framework-imposed security requirements. Third, AgentConform, a two-phase conformance checker that (i)extracts normative clauses from protocol specifications into a typed Protocol~IR with explicit Protocol/Environment/Adversary action separation, (ii)compiles the IR into TLA+ models and model-checks them against AASM invariants, then (iii)replays counterexample traces against live SDK implementations to confirm findings. We introduce the Composition Safety (CS) principle: security properties that hold for individual protocols can break when protocols are composed through shared infrastructure. We demonstrate this with formal models of five protocol composition patterns, revealing cross-protocol design gaps that individual protocol analysis cannot detect. Preliminary application to representative agent protocols reveals recurrent gaps in credential lifecycle, consent enforcement, audit completeness, and composition safety. Some findings are under coordinated disclosure; full evaluation details will be released in the complete version.
format Preprint
id arxiv_https___arxiv_org_abs_2603_23801
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle AgentRFC: Security Design Principles and Conformance Testing for Agent Protocols
Zheng, Shenghan
Zhang, Qifan
Cryptography and Security
AI agent protocols -- including MCP, A2A, ANP, and ACP -- enable autonomous agents to discover capabilities, delegate tasks, and compose services across trust boundaries. Despite massive deployment (MCP alone has 97M+ monthly SDK downloads), no systematic security framework for these protocols exists. We present three contributions. First, the Agent Protocol Stack, a 6-layer architectural model that defines what a complete agent protocol must specify at each layer -- analogous to ITU-T X.800 for the OSI stack. Second, the Agent-Agnostic Security Model, 11 security principles formalized as TLA+ invariants, each tagged with a property taxonomy (spec-mandated, spec-recommended, aasm-hardening, aps-completeness) that distinguishes protocol non-conformance from framework-imposed security requirements. Third, AgentConform, a two-phase conformance checker that (i)extracts normative clauses from protocol specifications into a typed Protocol~IR with explicit Protocol/Environment/Adversary action separation, (ii)compiles the IR into TLA+ models and model-checks them against AASM invariants, then (iii)replays counterexample traces against live SDK implementations to confirm findings. We introduce the Composition Safety (CS) principle: security properties that hold for individual protocols can break when protocols are composed through shared infrastructure. We demonstrate this with formal models of five protocol composition patterns, revealing cross-protocol design gaps that individual protocol analysis cannot detect. Preliminary application to representative agent protocols reveals recurrent gaps in credential lifecycle, consent enforcement, audit completeness, and composition safety. Some findings are under coordinated disclosure; full evaluation details will be released in the complete version.
title AgentRFC: Security Design Principles and Conformance Testing for Agent Protocols
topic Cryptography and Security
url https://arxiv.org/abs/2603.23801