Security Layer

The Security Layer implements secure group communications using the Message Layer Security (MLS) protocol. This layer ensures end-to-end encryption, authentication, and access control across agent groups within the AGP ecosystem.

Overview

The security layer leverages MLS to provide:

Quantum-safe end-to-end encryption (QSE2EE) for group communications
Dynamic group membership management
Forward secrecy and post-compromise security
Scalable key management for large agent groups

Key Components

1. Group State Management

Maintains cryptographic group state
Handles member additions and removals
Manages group epoch changes
Processes key updates

2. Key Schedule

Derives encryption keys from group secrets
Implements MLS key schedule
Manages key rotations
Ensures forward secrecy

3. Message Protection

Encrypts group messages
Provides integrity protection
Implements sender authentication
Handles message sequencing

4. Authentication

Validates group members
Verifies message signatures
Manages identity credentials
Implements access control

Security Properties

Forward Secrecy: Ensures past communications remain secure if keys are compromised
Post-Compromise Security: Provides security guarantees after member compromise
Group Authentication: Verifies message origin within the group
Message Confidentiality: Protects message content from unauthorized access

Integration

The security layer integrates with:

Transport layer for secure message delivery
Session layer for maintaining secure contexts
Identity services for credential management

        graph TB
    %% Services
    AS[Authentication Service]
    DS[Delivery Service]

    %% Service Connection
    AS <--> DS

    %% Clients and Members
    Client1[Client 1]:::client
    Client2[Client 2]:::client
    Client3[Client 3]:::client

    %% Group Definition
    subgraph MLSGroup[MLS Group]
        Member1[Member 1]:::member
        Member2[Member 2]:::member
    end

    %% Client Authentication
    Client1 --> AS
    Client2 --> AS
    Client3 --> AS

    %% Client-DS Connections
    Client1 -.-> DS
    Client2 --> DS
    Client3 --> DS

    %% Member Associations
    Client2 === Member1
    Client3 === Member2

    %% Styles
    classDef service fill:#ffffff,stroke:#000000,stroke-width:2px
    classDef client fill:#f0f0f0,stroke:#000000,stroke-width:2px
    classDef member fill:#e0e0e0,stroke:#000000,stroke-width:2px

    class AS,DS service
    class Client1,Client2,Client3 client
    class Member1,Member2 member