InterSAGE: The Secure and Verifiable Interoperability Protocol for An Internet of Agents

2026-08-13

AI Summary

This work addresses the widespread lack of verifiable security guarantees in existing agent communication protocols regarding identity, authorization, capability assertions, and post-delegation accountability. It proposes a four-layer trust-native protocol architecture that, for the first time, unifies persistent identity (based on decentralized identifiers), capability-aware verifiable credential discovery, dynamic trust negotiation, and kernel-level cryptographic audit chains. The resulting trust substrate is decoupled from the underlying communication protocol, portable, and fully verifiable. Without relying on consensus-based ledgers, the framework enables cross-organizational binding of LLM agent identities, capability verification, fine-grained access control, and execution traceability, demonstrating superior security and functionality compared to over fifty existing protocol architectures.

Abstract

The emerging Internet of Agents enables LLM-powered agents to discover peers, invoke tools, and delegate tasks across organizational boundaries. Existing protocols increasingly define how agents exchange messages, but not how an agent proves its identity, authorization, advertised capabilities, or accountability after delegation. We present InterSAGE, a trust-native protocol suite that supplies this missing security substrate alongside, rather than in place of, communication protocols. InterSAGE comprises four layers: Persistent Identity, Discovery, Trust Negotiation, and Accountability. Its four core primitives are: (1) Agent Identity Cards that bind developer, code package, operator, and deployment context; (2) capability-aware discovery using DID-bound Verifiable Credential manifests; (3) trust negotiation combining monotonic capability attenuation with two-tier access control; and (4) kernel-mediated cryptographic audit trails that bind usage, delegation, and execution traces to agent identity without a consensus ledger. InterSAGE is designed to complement MCP, A2A, ANP, and AG-UI, allowing communication protocols to evolve independently while keeping trust semantics explicit, portable, and verifiable. We compare InterSAGE with more than 50 efforts spanning agent protocols, decentralized identity, OAuth/OIDC extensions, zero-trust governance, delegation, and audit architectures. We show that no prior architecture jointly enforces persistent identity, capability-aware discovery, trust negotiation, and accountability as a unified four-layer trust substrate for secure agent interoperability.

Problem

• Internet of Agents
• agent interoperability
• trust
• identity verification
• accountability

Innovation

• InterSAGE
• Verifiable Credentials
• Decentralized Identity (DID)
• Trust Negotiation
• Cryptographic Audit Trail