Cross-Domain Interoperability Framework for AI Agent Collaboration
draft-cui-dmsc-agent-cdi-00
This document is an Internet-Draft (I-D).
Anyone may submit an I-D to the IETF.
This I-D is not endorsed by the IETF and has no formal standing in the
IETF standards process.
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Author | Yong Cui | ||
| Last updated | 2026-02-10 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-cui-dmsc-agent-cdi-00
WG Working Group Y. Cui
Internet-Draft Tsinghua University
Intended status: Informational 11 February 2026
Expires: 15 August 2026
Cross-Domain Interoperability Framework for AI Agent Collaboration
draft-cui-dmsc-agent-cdi-00
Abstract
This document defines a framework for enabling seamless cross-domain
interoperability among AI agents operating across different networks,
administrative domains, and heterogeneous platforms. The framework
addresses the challenges of identity federation, trust establishment,
policy harmonization, and secure communication that arise when AI
agents from distinct administrative realms need to collaborate on
shared tasks. It specifies mechanisms for agent discovery,
capability negotiation, trust delegation, and federated policy
enforcement, enabling scalable and secure multi-domain AI
collaboration without requiring centralized control.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-cui-dmsc-agent-cdi/.
Discussion of this document takes place on the WG Working Group
mailing list (mailto:WG@example.com), which is archived at
https://example.com/WG.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
Cui Expires 15 August 2026 [Page 1]
Internet-Draft CDI-Agent February 2026
This Internet-Draft will expire on 15 August 2026.
Copyright Notice
Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Cross-Domain Interoperability Framework . . . . . . . . . . . 6
4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. *Architecture Components* . . . . . . . . . . . . . . . . 6
4.2.1. Interoperability Gateway . . . . . . . . . . . . . . 7
4.2.2. Agent Registry and Directory . . . . . . . . . . . . 7
4.2.3. Cross-Domain Agent Runtime . . . . . . . . . . . . . 8
5. Trust Establishment Framework . . . . . . . . . . . . . . . . 8
5.1. Trust Model . . . . . . . . . . . . . . . . . . . . . . . 8
5.2. Trust Establishment Protocols . . . . . . . . . . . . . . 9
5.2.1. Domain Federation Protocol . . . . . . . . . . . . . 9
5.2.2. Agent Delegation Protocol . . . . . . . . . . . . . . 10
6. Identity and Access Management . . . . . . . . . . . . . . . 10
6.1. Federated Identity Model . . . . . . . . . . . . . . . . 10
6.1.1. Agent Identifiers . . . . . . . . . . . . . . . . . . 10
6.1.2. Credential Types . . . . . . . . . . . . . . . . . . 11
6.2. Access Control Framework . . . . . . . . . . . . . . . . 11
6.2.1. Multi-Domain Policy Model . . . . . . . . . . . . . . 11
6.2.2. Policy Negotiation Protocol . . . . . . . . . . . . . 11
6.2.3. Attribute-Based Access Control (ABAC) . . . . . . . . 12
7. Capability Discovery and Negotiation . . . . . . . . . . . . 12
7.1. Capability Description Language . . . . . . . . . . . . . 12
7.2. Discovery Mechanisms . . . . . . . . . . . . . . . . . . 13
7.2.1. Directory-Based Discovery . . . . . . . . . . . . . . 13
7.2.2. Peer-to-Peer Discovery . . . . . . . . . . . . . . . 14
7.3. Capability Negotiation Protocol . . . . . . . . . . . . . 14
8. Communication Protocols . . . . . . . . . . . . . . . . . . . 15
8.1. Cross-Domain Message Format . . . . . . . . . . . . . . . 15
Cui Expires 15 August 2026 [Page 2]
Internet-Draft CDI-Agent February 2026
8.2. Communication Patterns . . . . . . . . . . . . . . . . . 16
8.2.1. Direct Agent-to-Agent Communication . . . . . . . . . 16
8.2.2. Gateway-Mediated Communication . . . . . . . . . . . 17
8.2.3. Store-and-Forward Communication . . . . . . . . . . . 17
8.3. Protocol Layering . . . . . . . . . . . . . . . . . . . . 17
9. Security Considerations . . . . . . . . . . . . . . . . . . . 18
9.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 18
9.2. Security Controls . . . . . . . . . . . . . . . . . . . . 18
9.2.1. Authentication and Authorization . . . . . . . . . . 18
9.2.2. Data Protection . . . . . . . . . . . . . . . . . . . 19
9.2.3. Monitoring and Detection . . . . . . . . . . . . . . 19
9.3. Security Assurance . . . . . . . . . . . . . . . . . . . 19
9.3.1. Trust Verification . . . . . . . . . . . . . . . . . 19
9.3.2. Audit and Accountability . . . . . . . . . . . . . . 20
10. Performance and Scalability . . . . . . . . . . . . . . . . . 20
10.1. Performance Metrics . . . . . . . . . . . . . . . . . . 20
10.2. Scalability Considerations . . . . . . . . . . . . . . . 20
10.2.1. Horizontal Scaling . . . . . . . . . . . . . . . . . 20
10.2.2. Federation Scaling . . . . . . . . . . . . . . . . . 21
10.3. Resource Management . . . . . . . . . . . . . . . . . . 21
10.3.1. Computational Resources . . . . . . . . . . . . . . 21
10.3.2. Network Resources . . . . . . . . . . . . . . . . . 21
11. Deployment Considerations . . . . . . . . . . . . . . . . . . 22
11.1. Deployment Models . . . . . . . . . . . . . . . . . . . 22
11.1.1. Centralized Gateway Model . . . . . . . . . . . . . 22
11.1.2. Distributed Gateway Model . . . . . . . . . . . . . 22
11.1.3. Hybrid Model . . . . . . . . . . . . . . . . . . . . 22
11.2. Integration with Existing Systems . . . . . . . . . . . 23
11.2.1. Legacy Agent Systems . . . . . . . . . . . . . . . . 23
11.2.2. Cloud and Edge Deployments . . . . . . . . . . . . . 23
11.3. Operational Considerations . . . . . . . . . . . . . . . 23
11.3.1. Monitoring and Management . . . . . . . . . . . . . 23
11.3.2. Update and Maintenance . . . . . . . . . . . . . . . 24
12. Use Cases and Examples . . . . . . . . . . . . . . . . . . . 24
12.1. Cross-Enterprise Supply Chain Optimization . . . . . . . 24
12.2. Smart City Federation . . . . . . . . . . . . . . . . . 25
12.3. Cross-Border Financial Services Collaboration . . . . . 25
12.4. Cross-Domain Emergency Response System . . . . . . . . . 26
12.5. Multi-Cloud AI Workload Orchestration . . . . . . . . . 28
12.6. International Research Data Commons . . . . . . . . . . 29
12.7. Smart Manufacturing Supply Chain . . . . . . . . . . . . 30
12.8. Cross-Jurisdictional Law Enforcement Collaboration . . . 31
12.9. Global Energy Grid Coordination . . . . . . . . . . . . 32
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 33
14. Normative References . . . . . . . . . . . . . . . . . . . . 33
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 34
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 34
Cui Expires 15 August 2026 [Page 3]
Internet-Draft CDI-Agent February 2026
1. Introduction
The proliferation of AI agents across different organizational
boundaries has created a need for mechanisms that enable these agents
to collaborate effectively across domains. Traditional agent systems
are typically designed to operate within a single administrative
domain, where trust relationships, identity management, and policy
enforcement are centrally controlled. However, real-world
applications increasingly require AI agents to work together across
organizational boundaries, such as in supply chain optimization,
cross-enterprise workflow automation, smart city coordination, and
distributed scientific research.
Cross-domain interoperability for AI agents presents several unique
challenges:
1. *Trust Establishment*: How to establish and verify trust between
agents from different administrative domains without a central
authority.
2. *Identity Federation*: How to manage agent identities and
credentials across domains while preserving privacy and
sovereignty.
3. *Policy Harmonization*: How to reconcile potentially conflicting
policies from different domains to enable collaborative
operations.
4. *Capability Discovery*: How agents can discover and understand
the capabilities of foreign agents while respecting domain
boundaries.
5. *Secure Communication*: How to establish secure communication
channels that cross domain boundaries with appropriate security
guarantees.
6. *Accountability and Auditing*: How to maintain accountability for
actions taken by federated agents while respecting domain
autonomy.
This document proposes a framework that addresses these challenges
through a combination of federated trust mechanisms, standardized
capability descriptions, policy negotiation protocols, and secure
communication patterns. The framework is designed to be
incrementally deployable and compatible with existing single-domain
agent architectures.
Cui Expires 15 August 2026 [Page 4]
Internet-Draft CDI-Agent February 2026
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119] .
3. Terminology
The following terms are defined in this draft
* *MCP (Model Context Protocol)*: A protocol that standardizes tool
invocation and data interaction between AI agents and external
hosts using JSON-RPC over stdio or HTTP.
* *Host*: The process or service that provides tools or resources to
the agent via MCP, typically running as a backend process or
plugin.
* *Agent*: An AI entity that uses MCP to invoke external tools to
accomplish tasks.
* *Security Enhancement Layer (SEL)*: An external security layer
that provides transparent security controls for MCP communication
without protocol modification.
* *Client Shield*: The security component deployed on the MCP client
(Host) side, responsible for protecting user interests.
* *Server Shield*: The security component deployed on the MCP server
(tool provider) side, responsible for protecting service provider
interests.
* *Data Backflow*: The transmission of sensitive data from the agent
environment to external tools beyond authorized scope or without
proper safeguards.
* *Dual Authorization*: An authorization model requiring both
platform policy validation and explicit user consent for sensitive
operations.
* *Trace ID*: A globally unique identifier used to correlate events
across the MCP communication chain for auditing and
troubleshooting.
The following abbreviations are used in this document:
* *CDI*: Cross-Domain Interoperability
Cui Expires 15 August 2026 [Page 5]
Internet-Draft CDI-Agent February 2026
* *CDA*: Cross-Domain Agent
* *FIM*: Federated Identity Management
* *ABAC*: Attribute-Based Access Control
* *REST*: Representational State Transfer
* *JWT*: JSON Web Token
* *OIDC*: OpenID Connect
* *SAML*: Security Assertion Markup Language
* *DID*: Decentralized Identifier
* *VC*: Verifiable Credential
4. Cross-Domain Interoperability Framework
4.1. Overview
The Cross-Domain Interoperability Framework for AI Agents is designed
as a federated architecture that enables secure and scalable
collaboration between agents from different administrative domains.
The framework operates on several key principles:
1. *Domain Autonomy*: Each administrative domain maintains control
over its own agents, policies, and resources.
2. *Minimal Trust Assumptions*: Domains establish trust
relationships only as needed for specific collaborations.
3. *Graduated Interoperability*: Domains can choose different levels
of integration based on trust and requirements.
4. *Auditability*: All cross-domain interactions are logged and
auditable by all participating domains.
5. *Fail-Safe Design*: System failures or malicious actions in one
domain should not compromise other domains.
4.2. *Architecture Components*
The framework consists of the following core components:
Cui Expires 15 August 2026 [Page 6]
Internet-Draft CDI-Agent February 2026
+----------------+ +------------------+ +----------------+
| Domain A | | Interoperability | | Domain B |
| Administration |<----->| Gateway |<----->| Administration |
| & Control | | Federation | | & Control |
+----------------+ +------------------+ +----------------+
| | |
| (Home Domain) |(Gateway-mediated) |(Home Domain)
v v v
+----------------+ +------------------+ +----------------+
| Agent Registry | | Trust Broker | | Agent Registry |
| & Directory | | & Policy Engine| | & Directory |
+----------------+ +------------------+ +----------------+
| | |
| (Local Agents) |(Cross-Domain Agents) |(Local Agents)
v v v
+----------------+ +------------------+ +----------------+
| AI Agent A1 |<----->| AI Agent A2 |<----->| AI Agent B1 |
| (Domain A) | | (Domain A, | | (Domain B) |
| | | operating in | | |
| AI Agent A3 | | Domain B) | | AI Agent B2 |
| (Domain A) | +------------------+ | (Domain B) |
+----------------+ +----------------+
4.2.1. Interoperability Gateway
The Interoperability Gateway serves as the primary interface between
domains, providing:
* *Trust Brokerage*: Mediates trust establishment between domains
using verifiable credentials and reputation systems.
* *Policy Mediation*: Translates and reconciles policies between
domains to enable collaborative operations.
* *Agent Discovery*: Facilitates discovery of agents and their
capabilities across domain boundaries.
* *Communication Routing*: Routes messages between agents in
different domains with appropriate security.
* *Audit Collection*: Collects and correlates audit trails from
cross-domain interactions.
4.2.2. Agent Registry and Directory
Each domain maintains an Agent Registry that provides:
Cui Expires 15 August 2026 [Page 7]
Internet-Draft CDI-Agent February 2026
* *Local Agent Directory*: Catalog of agents within the domain with
their capabilities and status.
* *Foreign Agent Cache*: Cached information about agents from other
domains that have been authorized to operate locally.
* *Capability Repository*: Structured descriptions of agent
capabilities using standardized schemas.
* *Policy Repository*: Storage for domain-specific policies
governing agent behavior.
4.2.3. Cross-Domain Agent Runtime
Agents operating in foreign domains require enhanced runtime
components:
* *Policy Compliance Engine*: Ensures agent behavior complies with
both home and foreign domain policies.
* *Context Adaptation Module*: Adapts agent behavior based on the
operating context and domain-specific requirements.
* *Secure Communication Module*: Implements cross-domain
communication protocols with end-to-end security.
* *Audit Logging Module*: Maintains detailed logs of all cross-
domain operations for accountability.
5. Trust Establishment Framework
5.1. Trust Model
The framework employs a multi-layered trust model:
1. *Domain-to-Domain Trust*: Established through bilateral
agreements, verifiable credentials, or reputation systems.
2. *Agent-to-Agent Trust*: Derived from domain trust but enhanced
with agent-specific credentials and behavioral attestations.
3. *Task-Specific Trust*: Limited trust established for specific
collaborative tasks with clearly defined boundaries.
4. *Revocable Trust*: All trust relationships are time-bound and
revocable by any participating domain.
Cui Expires 15 August 2026 [Page 8]
Internet-Draft CDI-Agent February 2026
5.2. Trust Establishment Protocols
5.2.1. Domain Federation Protocol
Domains establish trust relationships through a multi-phase protocol:
Phase 1: Discovery and Introduction
+-----------+ +-----------+ +-----------+
| Domain A | | Discovery | | Domain B |
| | | Service | | |
+-----------+ +-----------+ +-----------+
| | |
| 1. Query for compatible| |
| partners | |
|----------------------->| |
| | |
| 2. Return list of | |
| potential partners | |
|<-----------------------| |
| | |
| 3. Request introduction| |
| to Domain B | |
|----------------------->| |
| | |
| 4. Forward introduction| |
| request | |
| |----------------------->|
| | |
Phase 2: Capability and Policy Exchange
| | |
| 5. Send capability | |
| profile and policy | |
| assertions | |
|<------------------------------------------------|
| | |
| 6. Evaluate compatibility| |
| and risk | |
|------------------------------------------------>|
| | |
Phase 3: Trust Agreement
| | |
| 7. Propose trust | |
| agreement with terms| |
Cui Expires 15 August 2026 [Page 9]
Internet-Draft CDI-Agent February 2026
| and conditions | |
|<------------------------------------------------|
| | |
| 8. Negotiate and | |
| finalize agreement | |
|------------------------------------------------>|
| | |
| 9. Exchange signed | |
| trust certificates | |
|<------------------------------------------------|
| | |
5.2.2. Agent Delegation Protocol
Once domains establish trust, agents can be delegated to operate in
foreign domains:
1. *Delegation Request*: Home domain requests delegation for
specific agents with defined capabilities and constraints.
2. *Policy Alignment*: Foreign domain evaluates the request against
its policies and may negotiate constraints.
3. *Credential Issuance*: Home domain issues verifiable credentials
to agents for use in the foreign domain.
4. *Local Registration*: Agents register with the foreign domain's
Agent Registry using their credentials.
5. *Periodic Revalidation*: Delegated credentials are periodically
revalidated and can be revoked at any time.
6. Identity and Access Management
6.1. Federated Identity Model
The framework employs a federated identity model with the following
components:
6.1.1. Agent Identifiers
Each agent has multiple identifiers for different contexts:
* *Home Domain Identifier*: Unique identifier within the home domain
(e.g., UUID, email-style address).
* *Federated Identifier*: Globally unique identifier for cross-
domain recognition (e.g., DID, URN).
Cui Expires 15 August 2026 [Page 10]
Internet-Draft CDI-Agent February 2026
* *Session Identifiers*: Temporary identifiers for specific
collaborative sessions.
6.1.2. Credential Types
* *Domain Identity Credentials*: Verifiable credentials issued by
the home domain attesting to the agent's identity and basic
attributes.
* *Capability Credentials*: Credentials attesting to specific agent
capabilities and skill levels.
* *Delegation Credentials*: Credentials authorizing an agent to
operate in a foreign domain with specific permissions.
* *Task Credentials*: Limited-scope credentials for specific
collaborative tasks.
6.2. Access Control Framework
6.2.1. Multi-Domain Policy Model
Access control decisions consider policies from multiple domains:
Access Decision = f(Home Domain Policy, Foreign Domain Policy,
Collaborative Task Policy, Dynamic Context Factors)
6.2.2. Policy Negotiation Protocol
When policies conflict, domains negotiate to find acceptable
compromises:
1. *Policy Disclosure*: Domains share relevant policy fragments (not
necessarily complete policies).
2. *Conflict Detection*: Identify conflicts between policies from
different domains.
3. *Resolution Proposal*: Propose policy modifications or exceptions
to resolve conflicts.
4. *Agreement Finalization*: Domains agree on a merged policy for
the specific collaboration.
5. *Policy Enforcement*: The agreed policy is enforced by all
participating domains.
Cui Expires 15 August 2026 [Page 11]
Internet-Draft CDI-Agent February 2026
6.2.3. Attribute-Based Access Control (ABAC)
The framework uses ABAC with attributes from multiple sources:
* *Agent Attributes*: Identity, capabilities, reputation score, home
domain.
* *Resource Attributes*: Sensitivity, ownership, location,
classification.
* *Environmental Attributes*: Time, network location, threat level.
* *Collaboration Attributes*: Task type, participating domains,
trust level.
7. Capability Discovery and Negotiation
7.1. Capability Description Language
Agents describe their capabilities using a structured language based
on JSON Schema:
Cui Expires 15 August 2026 [Page 12]
Internet-Draft CDI-Agent February 2026
{
"agent_capability_profile": {
"version": "1.0",
"agent_id": "did:example:agent123",
"home_domain": "example.com",
"capabilities": [
{
"capability_id": "natural_language_processing",
"category": "ai_processing",
"subcategories": ["text_analysis", "sentiment_analysis"],
"performance_metrics": {
"accuracy": 0.92,
"latency_ms": 150,
"throughput_rps": 100
},
"input_formats": ["text/plain", "application/json"],
"output_formats": ["application/json"],
"privacy_attributes": {
"data_retention": "ephemeral",
"data_sharing": "none"
},
"resource_requirements": {
"compute_units": 2,
"memory_mb": 512,
"network_bandwidth_mbps": 10
}
}
],
"constraints": {
"max_concurrent_tasks": 5,
"supported_domains": ["example.com", "partner.org"],
"geographic_restrictions": ["US", "EU"],
"compliance_frameworks": ["GDPR", "HIPAA"]
}
}
}
7.2. Discovery Mechanisms
7.2.1. Directory-Based Discovery
Domains publish authorized agent capabilities in federated
directories:
1. *Local Directory Registration*: Agents register capabilities with
their home domain directory.
Cui Expires 15 August 2026 [Page 13]
Internet-Draft CDI-Agent February 2026
2. *Federated Directory Sync*: Domain directories synchronize
authorized capability information.
3. *Query Interface*: Agents query directories to discover
capabilities across domains.
4. *Privacy-Preserving Queries*: Support for capability discovery
without revealing specific agent identities when not needed.
7.2.2. Peer-to-Peer Discovery
For dynamic or ad-hoc collaborations:
1. *Capability Advertisement*: Agents broadcast capability summaries
within trusted networks.
2. *Matchmaking Services*: Third-party services match agents with
complementary capabilities.
3. *Reputation-Based Discovery*: Discover agents based on reputation
scores from previous collaborations.
7.3. Capability Negotiation Protocol
When agents with complementary capabilities are identified:
Cui Expires 15 August 2026 [Page 14]
Internet-Draft CDI-Agent February 2026
+-----------+ +-----------+ +-----------+
| Agent A | | Gateway | | Agent B |
| (Domain X)| | | | (Domain Y)|
+-----------+ +-----------+ +-----------+
| | |
| 1. Initiate collaboration | |
| request | |
|--------------------------->| |
| | |
| | 2. Forward to suitable |
| | partner (Agent B) |
| |-------------------------->|
| | 3. Return capability |
| | requirements and |
| | constraints |
| |<--------------------------|
| | |
| 4. Check compatibility and | |
| policy compliance | |
|<---------------------------| |
| | |
| 5. Negotiate specific | |
| parameters (quality, | |
| cost, timing) | |
|--------------------------->| |
| |-------------------------->|
| | 6. Reach agreement |
| | |
| |<--------------------------|
| | |
| 7. Finalize collaboration | |
| contract | |
|<---------------------------| |
| | |
8. Communication Protocols
8.1. Cross-Domain Message Format
All cross-domain messages use a standardized envelope format:
Cui Expires 15 August 2026 [Page 15]
Internet-Draft CDI-Agent February 2026
{
"message_envelope": {
"version": "1.0",
"message_id": "urn:uuid:550e8400-e29b-41d4-a716-446655440000",
"timestamp": "2024-01-15T10:30:00Z",
"sender": {
"agent_id": "did:example:sender123",
"domain": "example.com",
"credentials": ["vc:example:credential456"]
},
"recipient": {
"agent_id": "did:example:recipient789",
"domain": "partner.org"
},
"routing": {
"path": ["gateway.example.com", "gateway.partner.org"],
"hops": 2,
"ttl": 3600
},
"security": {
"encryption": "A256GCM",
"signature": "ES256",
"integrity_protection": true
},
"payload": {
"type": "task_request",
"content": "Base64-encoded encrypted payload",
"content_type": "application/json"
},
"metadata": {
"priority": "normal",
"response_required": true,
"audit_trail_id": "audit:example:trail123"
}
}
}
8.2. Communication Patterns
8.2.1. Direct Agent-to-Agent Communication
For high-trust, high-performance scenarios:
1. *Tunnel Establishment*: Establish secure tunnels through domain
gateways.
2. *Peer Authentication*: Mutual authentication using domain-issued
credentials.
Cui Expires 15 August 2026 [Page 16]
Internet-Draft CDI-Agent February 2026
3. *End-to-End Encryption*: Application-layer encryption independent
of transport security.
4. *Heartbeat Monitoring*: Continuous monitoring of connection
health and security.
8.2.2. Gateway-Mediated Communication
For enhanced security and policy enforcement:
1. *Message Inspection*: Gateways inspect messages for policy
compliance.
2. *Content Transformation*: Gateways may transform content to meet
domain requirements.
3. *Quality of Service*: Gateways provide QoS guarantees for cross-
domain communication.
4. *Load Balancing*: Gateways distribute traffic across multiple
agent instances.
8.2.3. Store-and-Forward Communication
For disconnected or asynchronous operations:
1. *Message Queuing*: Gateways queue messages when recipients are
unavailable.
2. *Delivery Guarantees*: Configurable delivery guarantees (at-most-
once, at-least-once, exactly-once).
3. *Priority Handling*: Priority-based message scheduling and
delivery.
4. *Dead Letter Handling*: Processing of undeliverable messages.
8.3. Protocol Layering
The communication protocol stack for cross-domain agent interaction:
Cui Expires 15 August 2026 [Page 17]
Internet-Draft CDI-Agent February 2026
+-----------------------------------------------------+
| Application-Specific Protocols |
| (Task coordination, data exchange, collaboration) |
+-----------------------------------------------------+
| Cross-Domain Agent Messaging Protocol |
| (Envelope format, routing, reliability, QoS) |
+-----------------------------------------------------+
| Security Layer Protocol |
| (Authentication, encryption, integrity, nonce) |
+-----------------------------------------------------+
| Trust Layer Protocol |
| (Credential verification, policy enforcement) |
+-----------------------------------------------------+
| Transport Layer Protocol |
| (HTTP/2, WebSocket, MQTT, AMQP) |
+-----------------------------------------------------+
9. Security Considerations
9.1. Threat Model
The framework addresses the following threat vectors:
1. *Impersonation Attacks*: Malicious agents pretending to be
legitimate agents from trusted domains.
2. *Policy Bypass Attacks*: Attempts to circumvent domain policies
through technical or procedural means.
3. *Data Exfiltration*: Unauthorized transfer of sensitive data
across domain boundaries.
4. *Denial of Service*: Attacks targeting the availability of cross-
domain collaboration services.
5. *Trust Exploitation*: Abuse of trust relationships to gain
unauthorized access or privileges.
6. *Audit Tampering*: Attempts to modify or delete audit logs to
conceal malicious activities.
9.2. Security Controls
9.2.1. Authentication and Authorization
* *Multi-Factor Authentication*: Require multiple credentials for
sensitive operations.
Cui Expires 15 August 2026 [Page 18]
Internet-Draft CDI-Agent February 2026
* *Continuous Authentication*: Re-authenticate agents periodically
during long sessions.
* *Context-Aware Authorization*: Adjust permissions based on dynamic
risk assessments.
* *Least Privilege Enforcement*: Grant minimal necessary permissions
for each task.
9.2.2. Data Protection
* *End-to-End Encryption*: Encrypt sensitive data throughout its
lifecycle.
* *Data Minimization*: Transfer only necessary data for each
collaboration.
* *Privacy-Preserving Computation*: Use techniques like federated
learning and secure multi-party computation.
* *Data Sovereignty*: Respect data sovereignty requirements of each
domain.
9.2.3. Monitoring and Detection
* *Behavioral Analytics*: Monitor agent behavior for anomalies
indicative of compromise.
* *Cross-Domain Correlation*: Correlate security events across
multiple domains.
* *Real-Time Threat Intelligence*: Integrate threat intelligence
feeds from all participating domains.
* *Automated Response*: Automated containment and mitigation of
detected threats.
9.3. Security Assurance
9.3.1. Trust Verification
* *Credential Chain Validation*: Verify the complete chain of
credentials from root authorities.
* *Revocation Checking*: Continuously check credential revocation
status.
Cui Expires 15 August 2026 [Page 19]
Internet-Draft CDI-Agent February 2026
* *Reputation Scoring*: Use reputation systems to assess agent
trustworthiness.
* *Behavioral Attestation*: Use remote attestation to verify agent
integrity.
9.3.2. Audit and Accountability
* *Immutable Audit Logs*: Store audit logs in tamper-evident
storage.
* *Cross-Domain Audit Correlation*: Enable correlation of audit
trails across domains.
* *Non-Repudiation*: Ensure agents cannot deny actions they have
taken.
* *Forensic Readiness*: Maintain evidence for potential legal or
investigative proceedings.
10. Performance and Scalability
10.1. Performance Metrics
The framework defines the following performance metrics:
1. *Discovery Latency*: Time to discover suitable collaboration
partners (target: < 5 seconds for 95% of queries).
2. *Trust Establishment Time*: Time to establish trust between
previously unknown domains (target: < 30 seconds).
3. *Message Delivery Latency*: End-to-end latency for cross-domain
messages (target: < 100ms for 95% of messages within same
region).
4. *Policy Evaluation Time*: Time to evaluate access control
policies (target: < 10ms per decision).
5. *Agent Registration Time*: Time for an agent to register in a
foreign domain (target: < 2 seconds).
10.2. Scalability Considerations
10.2.1. Horizontal Scaling
* *Stateless Design*: Design components to be stateless where
possible for easy scaling.
Cui Expires 15 August 2026 [Page 20]
Internet-Draft CDI-Agent February 2026
* *Load Distribution*: Distribute load across multiple instances of
each component.
* *Geographic Distribution*: Deploy components in multiple
geographic regions.
* *Caching Strategy*: Implement multi-level caching to reduce
backend load.
10.2.2. Federation Scaling
* *Hierarchical Federation*: Organize domains into hierarchies to
reduce pairwise trust relationships.
* *Transitive Trust*: Support transitive trust with appropriate
safeguards.
* *Partial Mesh Networks*: Optimize trust relationships based on
collaboration patterns.
* *Domain Clustering*: Group domains with frequent collaborations to
reduce overhead.
10.3. Resource Management
10.3.1. Computational Resources
* *Elastic Scaling*: Automatically scale resources based on demand.
* *Resource Quotas*: Enforce resource quotas per domain and per
agent.
* *Efficient Algorithms*: Use computationally efficient algorithms
for cryptographic operations.
* *Hardware Acceleration*: Leverage hardware acceleration for
performance-critical operations.
10.3.2. Network Resources
* *Bandwidth Management*: Prioritize cross-domain traffic based on
importance.
* *Connection Pooling*: Reuse connections to reduce connection
establishment overhead.
* *Compression*: Compress messages to reduce bandwidth usage.
Cui Expires 15 August 2026 [Page 21]
Internet-Draft CDI-Agent February 2026
* *Adaptive Protocols*: Use protocols that adapt to network
conditions.
11. Deployment Considerations
11.1. Deployment Models
11.1.1. Centralized Gateway Model
* *Description*: All cross-domain traffic flows through centralized
interoperability gateways.
* *Advantages*: Simplified management, consistent policy
enforcement, comprehensive auditing.
* *Disadvantages*: Single point of failure, potential performance
bottleneck, higher latency.
* *Use Cases*: Highly regulated environments, initial deployments,
domains with limited technical resources.
11.1.2. Distributed Gateway Model
* *Description*: Each domain operates its own gateway, with gateways
forming a peer-to-peer network.
* *Advantages*: No single point of failure, better performance,
preserves domain autonomy.
* *Disadvantages*: More complex to manage, requires inter-gateway
trust establishment.
* *Use Cases*: Large-scale deployments, domains with technical
expertise, performance-sensitive applications.
11.1.3. Hybrid Model
* *Description*: Combination of centralized and distributed elements
based on requirements.
* *Advantages*: Flexibility to optimize for different use cases,
incremental deployment.
* *Disadvantages*: Increased complexity, potential consistency
challenges.
* *Use Cases*: Evolving deployments, heterogeneous domain
environments, transitional architectures.
Cui Expires 15 August 2026 [Page 22]
Internet-Draft CDI-Agent February 2026
11.2. Integration with Existing Systems
11.2.1. Legacy Agent Systems
* *Wrapper Components*: Develop wrappers that enable legacy agents
to participate in cross-domain collaborations.
* *Protocol Translation*: Translate between legacy protocols and the
cross-domain interoperability protocols.
* *Policy Mapping*: Map legacy policy mechanisms to the framework's
policy model.
* *Gradual Migration*: Support gradual migration from legacy systems
to native implementations.
11.2.2. Cloud and Edge Deployments
* *Cloud-Native Design*: Design components as cloud-native
microservices.
* *Edge Optimization*: Optimize for edge deployments with limited
resources.
* *Hybrid Cloud Support*: Support deployments spanning multiple
cloud providers and on-premises infrastructure.
* *Containerization*: Package components as containers for easy
deployment.
11.3. Operational Considerations
11.3.1. Monitoring and Management
* *Unified Dashboard*: Provide a unified dashboard for monitoring
cross-domain collaborations.
* *Health Checks*: Implement comprehensive health checks for all
components.
* *Alerting System*: Configurable alerting for security events and
performance issues.
* *Capacity Planning*: Tools for capacity planning and resource
allocation.
Cui Expires 15 August 2026 [Page 23]
Internet-Draft CDI-Agent February 2026
11.3.2. Update and Maintenance
* *Rolling Updates*: Support rolling updates without disrupting
ongoing collaborations.
* *Version Compatibility*: Maintain compatibility between different
versions of the framework.
* *Backward Compatibility*: Ensure new versions don't break existing
deployments.
* *Migration Tools*: Provide tools for migrating between framework
versions.
12. Use Cases and Examples
12.1. Cross-Enterprise Supply Chain Optimization
*Scenario*: Multiple companies in a supply chain need to collaborate
using AI agents to optimize inventory, logistics, and production
scheduling.
*Challenges*:
* Each company has its own systems, policies, and data sovereignty
requirements.
* Sensitive business information must not be exposed to competitors.
* Real-time coordination is needed across organizational boundaries.
*Solution using CDI Framework*:
1. Each company deploys an interoperability gateway.
2. Supply chain partners establish limited trust relationships for
specific collaboration areas.
3. Agents are delegated with carefully constrained capabilities for
supply chain optimization.
4. Privacy-preserving techniques (like federated learning) are used
to train optimization models without sharing raw data.
5. Audit trails are maintained for compliance and dispute
resolution.
Cui Expires 15 August 2026 [Page 24]
Internet-Draft CDI-Agent February 2026
12.2. Smart City Federation
*Scenario*: Multiple municipalities want to collaborate on smart city
initiatives while maintaining control over their own infrastructure
and data.
*Challenges*:
* Different municipalities have different regulations and policies.
* Citizens' privacy must be protected across jurisdictional
boundaries.
* Emergency situations require rapid coordination.
*Solution using CDI Framework*:
1. Each municipality operates as an independent domain.
2. A federation agreement establishes baseline trust and policies.
3. Specialized agents for traffic management, emergency response,
and utility optimization can operate across municipalities.
4. Data sharing follows strict privacy-preserving protocols.
5. During emergencies, trust levels can be temporarily elevated to
enable faster coordination.
12.3. Cross-Border Financial Services Collaboration
*Scenario*: Financial institutions across different regulatory
jurisdictions need AI agents to collaborate on fraud detection, risk
assessment, and compliance monitoring while adhering to strict
regulatory requirements.
*Challenges*:
* Different countries have different financial regulations and
compliance requirements.
* Sensitive customer financial data cannot be freely shared across
borders.
* Real-time fraud detection requires rapid information exchange
while maintaining data privacy.
Cui Expires 15 August 2026 [Page 25]
Internet-Draft CDI-Agent February 2026
* Audit trails must be comprehensive and legally admissible in
multiple jurisdictions.
*Solution using CDI Framework*:
1. Each financial institution operates within its regulatory domain
with institution-specific policies.
2. Cross-border trust agreements are established with legal and
regulatory compliance baked into the trust parameters.
3. Specialized agents for fraud pattern recognition can operate
across institutions using privacy-preserving techniques like
federated learning.
4. Regulatory compliance agents ensure all cross-border operations
adhere to applicable laws (e.g., GDPR, CCPA, Basel III).
5. All transactions are logged with cryptographic proofs that can be
verified by regulators in any jurisdiction.
*Key Technical Features*:
* *Regulatory Policy Engines*: Each domain includes policy engines
that encode jurisdictional regulations.
* *Privacy-Preserving Analytics*: Use of homomorphic encryption for
cross-institution fraud pattern analysis without exposing raw
transaction data.
* *Multi-Jurisdictional Audit*: Audit logs structured to meet
requirements of multiple regulatory bodies simultaneously.
* *Emergency Override Protocols*: Controlled mechanisms for
temporary policy relaxation during financial crises or systemic
risk events.
12.4. Cross-Domain Emergency Response System
*Scenario*: During natural disasters, public health emergencies, or
cybersecurity incidents, AI agents from different organizations need
to coordinate rapid response while maintaining security boundaries
and respecting organizational autonomy.
*Challenges*:
* Time-critical operations requiring collaboration establishment
within minutes.
Cui Expires 15 August 2026 [Page 26]
Internet-Draft CDI-Agent February 2026
* Different organizations have varying command hierarchies and
decision-making processes.
* Sensitive information must be shared only within necessary scope.
* Resource constraints during emergencies may affect communication
reliability.
* Post-emergency accountability and after-action analysis
requirements.
*Solution using CDI Framework*:
1. *Pre-Established Trust Frameworks*: Organizations establish
baseline trust relationships and policies during peacetime.
2. *Emergency Trust Elevation*: During declared emergencies, trust
levels can be temporarily elevated with appropriate safeguards
and post-event review requirements.
3. *Dynamic Policy Adaptation*: Emergency-specific policies override
normal operating policies temporarily.
4. *Resource Pooling Coordination*: AI agents coordinate resource
allocation across organizational boundaries while maintaining
ownership tracking.
5. *Situational Awareness Sharing*: Secure sharing of situational
data with granular access controls based on role and need-to-
know.
*Implementation Components*:
* *Emergency Declaration Protocol*: Standardized mechanism for
organizations to declare emergencies and activate enhanced
collaboration modes.
* *Priority Communication Channels*: Dedicated, high-priority
communication paths for emergency coordination.
* *Resource Discovery and Allocation*: Dynamic discovery of
available resources (personnel, equipment, facilities) across
participating organizations.
* *Common Operational Picture*: Federated data aggregation to create
unified situational awareness without centralizing sensitive
information.
Cui Expires 15 August 2026 [Page 27]
Internet-Draft CDI-Agent February 2026
*Example Flow - Natural Disaster Response*:
1. Earthquake occurs affecting multiple jurisdictions.
2. Emergency services from affected areas declare emergencies
through their interoperability gateways.
3. Trust levels are automatically elevated based on pre-configured
emergency protocols.
4. AI agents from different emergency services discover each other's
capabilities through federated directories.
5. Resource coordination agents negotiate allocation of search-and-
rescue teams, medical supplies, and evacuation routes.
6. Privacy-preserving techniques allow sharing of victim location
data while protecting personally identifiable information.
7. Post-event, all actions are audited, trust levels revert to
normal, and after-action reports are generated from the
comprehensive audit logs.
12.5. Multi-Cloud AI Workload Orchestration
*Scenario*: Enterprises running AI workloads across multiple cloud
providers need agents to manage resources, optimize costs, and ensure
compliance while avoiding vendor lock-in.
*Challenges*:
* Different cloud providers have proprietary APIs and management
interfaces.
* Data sovereignty requirements may restrict where workloads can
run.
* Cost optimization requires dynamic workload migration across
providers.
* Security policies must be consistently enforced across
heterogeneous environments.
*Solution using CDI Framework*:
1. Each cloud environment operates as a separate domain with cloud-
specific policies and capabilities.
Cui Expires 15 August 2026 [Page 28]
Internet-Draft CDI-Agent February 2026
2. Enterprise governance domain defines overarching policies that
apply across all cloud domains.
3. Orchestration agents operate across cloud domains to optimize
workload placement based on cost, performance, and compliance
requirements.
4. Data movement agents manage secure data transfer between cloud
environments with appropriate encryption and access controls.
5. Compliance monitoring agents ensure consistent policy enforcement
regardless of where workloads execute.
*Technical Implementation*:
* *Cloud Abstraction Layer*: Standardized interface that abstracts
cloud provider differences.
* *Cost Optimization Engine*: AI agents that analyze pricing models
and performance metrics to recommend optimal workload placement.
* *Data Gravity Management*: Intelligent agents that minimize data
movement costs by colocating computation with data.
* *Compliance Mapping*: Automated mapping of cloud provider
compliance certifications to enterprise regulatory requirements.
12.6. International Research Data Commons
*Scenario*: Global research collaborations need to share and analyze
sensitive research data (e.g., genomic data, climate data,
epidemiological data) while protecting participant privacy and
respecting national data sovereignty laws.
*Challenges*:
* Research data often contains sensitive personal information with
strict privacy requirements.
* Different countries have different data protection laws and
ethical review requirements.
* Researchers need to collaborate on analysis while maintaining
control over their contributed data.
* Funding agencies require accountability for data usage and
research outputs.
Cui Expires 15 August 2026 [Page 29]
Internet-Draft CDI-Agent February 2026
*Solution using CDI Framework*:
1. Each research institution operates as an independent domain with
institutional review board (IRB) approved policies.
2. Research consortia establish collaboration domains with
consortium-specific policies that respect all member
institutions' requirements.
3. Data analysis agents operate on federated data without needing to
centralize sensitive information.
4. Publication agents coordinate multi-institution authorship and
ensure proper attribution.
5. Data usage tracking agents monitor compliance with data use
agreements across all participating institutions.
*Key Features*:
* *Ethical Compliance Engine*: Automated checks for compliance with
ethical research standards across jurisdictions.
* *Differential Privacy Integration*: Built-in differential privacy
mechanisms for aggregate analysis.
* *Data Provenance Tracking*: Complete lineage tracking for research
data from collection through analysis to publication.
* *Automated Institutional Review*: Streamlined process for cross-
institutional research approval.
12.7. Smart Manufacturing Supply Chain
*Scenario*: Manufacturers, suppliers, and logistics providers in a
smart manufacturing ecosystem need to coordinate production,
inventory, and delivery using AI agents while protecting intellectual
property and competitive information.
*Challenges*:
* Competitors may be part of the same supply chain, requiring
information boundaries.
* Real-time coordination needed for just-in-time manufacturing and
inventory management.
Cui Expires 15 August 2026 [Page 30]
Internet-Draft CDI-Agent February 2026
* Quality control data needs to flow upstream to suppliers without
revealing proprietary manufacturing processes.
* Cybersecurity threats targeting interconnected industrial control
systems.
*Solution using CDI Framework*:
1. Each company in the supply chain operates as an independent
domain with competitive boundary policies.
2. Supply chain collaboration domains establish limited information
sharing agreements for specific coordination tasks.
3. Production planning agents coordinate across organizations while
preserving competitive intelligence.
4. Quality monitoring agents share defect information with suppliers
without revealing manufacturing process details.
5. Cybersecurity monitoring agents collaborate on threat detection
while protecting each company's security posture information.
*Implementation Approach*:
* *Need-to-Know Information Sharing*: Granular controls on what
information is shared with which partners.
* *Competitive Boundary Management*: Clear policies defining what
constitutes competitive information that should not be shared.
* *Real-Time Coordination Protocols*: Low-latency communication for
time-sensitive manufacturing coordination.
* *Industrial IoT Security*: Specialized security protocols for
industrial control system integration.
12.8. Cross-Jurisdictional Law Enforcement Collaboration
*Scenario*: Law enforcement agencies from different jurisdictions
need to collaborate on investigations while respecting legal
boundaries, privacy laws, and chain of evidence requirements.
*Challenges*:
* Different legal systems have different requirements for evidence
collection and sharing.
Cui Expires 15 August 2026 [Page 31]
Internet-Draft CDI-Agent February 2026
* Privacy laws restrict sharing of personal information across
borders.
* Chain of custody must be maintained for digital evidence.
* Need for rapid information sharing in time-sensitive
investigations (e.g., kidnapping, terrorism).
*Solution using CDI Framework*:
1. Each law enforcement agency operates within its jurisdictional
domain with legally compliant policies.
2. Mutual legal assistance treaty (MLAT) frameworks are encoded into
trust agreements between domains.
3. Investigation coordination agents facilitate information sharing
within legal boundaries.
4. Evidence handling agents maintain chain of custody across
jurisdictional transfers.
5. Legal compliance agents ensure all cross-jurisdictional
operations adhere to applicable laws.
*Technical Considerations*:
* *Legal Authority Verification*: Automated verification of legal
authority for specific investigative actions.
* *Privacy-Preserving Matching*: Techniques for matching persons of
interest without sharing full identity information.
* *Digital Evidence Chain of Custody*: Cryptographic proof of
evidence integrity and custody chain.
* *Automated Legal Documentation*: Generation of legally required
documentation for cross-jurisdictional operations.
12.9. Global Energy Grid Coordination
*Scenario*: Energy providers, grid operators, and renewable energy
producers across regions need to coordinate energy production,
distribution, and consumption while maintaining grid stability and
respecting commercial interests.
*Challenges*:
Cui Expires 15 August 2026 [Page 32]
Internet-Draft CDI-Agent February 2026
* Different grid operators have proprietary control systems and
protocols.
* Renewable energy sources introduce variability requiring real-time
coordination.
* Commercial energy trading requires secure transaction mechanisms.
* Grid cybersecurity requires collaborative threat detection without
revealing vulnerability information.
*Solution using CDI Framework*:
1. Each energy provider and grid operator operates as an independent
domain.
2. Regional coordination domains establish protocols for grid
stability management.
3. Energy trading agents facilitate secure transactions across
organizational boundaries.
4. Grid optimization agents coordinate production and consumption
across regions.
5. Cybersecurity agents collaborate on threat detection while
protecting proprietary system information.
*Key Components*:
* *Grid Stability Protocols*: Standardized protocols for maintaining
grid stability across interconnected systems.
* *Renewable Integration Management*: Coordination of variable
renewable energy sources across the grid.
* *Secure Energy Trading*: Privacy-preserving mechanisms for energy
market transactions.
* *Grid Resilience Coordination*: Collaborative response to grid
disturbances and failures.
13. IANA Considerations
This document has no IANA actions.
14. Normative References
Cui Expires 15 August 2026 [Page 33]
Internet-Draft CDI-Agent February 2026
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
Acknowledgments
Author's Address
Yong Cui
Tsinghua University
Beijing, 100084
China
Email: cuiyong@tsinghua.edu.cn
URI: http://www.cuiyong.net/
Cui Expires 15 August 2026 [Page 34]