DEFONEOS · MCP Supply-Chain Integrity Scan

1. Overview

The MCP Supply-Chain Integrity Scan (SCIS) is a continuous auditing system that ensures the trustworthiness of all Model Context Protocol (MCP) servers and their dependencies within the DEFONEOS sovereign substrate. It is designed to detect tampering, vulnerabilities, and non-compliance with red-line policies.

Sovereignty invariant: Every component, from the operating system to the smallest Python package, is cryptographically verified against a UK-sovereign SBOM ledger. No unknown or untrusted code can execute within DEFONEOS.

2. Verification Layers

2.1 SBOM Generation and Tracking

Each MCP server and its build environment generates a comprehensive Software Bill of Materials (SBOM) in SPDX format. These SBOMs are signed with Ed25519 keys and stored in the SIGIL ledger.

Layer	Description	Verification Method
L1: OS / Kernel	Underlying operating system and kernel integrity	Kernel measurements (IMA/EVM), signed boot
L2: Base Image	Docker/VM base image integrity	Container image signing (cosign), digest verification
L3: System Dependencies	Installed system libraries (e.g., glibc, openssl)	Package manager integrity checks, SBOM comparison
L4: Python Environment	Python interpreter, virtual environment, pip packages	`pip check`, `poetry export --hashes`, PyPI signed packages
L5: MCP Codebase	The specific code for the MCP server itself	Git commit signing, Ed25519 source code attestations
L6: Model Artifacts	AI models, weights, tokenizers used by the MCP	Hugging Face Hub model signing, cryptographic hashes (SHA-256)
L7: Data Sources	External data feeds, APIs, datasets consumed by MCP	Source attestation (origin/integrity), mTLS to trusted endpoints

2.2 Ed25519 Signature Verification

Every SBOM, code commit, and model artifact within the supply chain is signed with an Ed25519 key. The SCIS continuously verifies these signatures against a trusted root of attestations stored in the BFT council's ledger.

# Pseudo-code for supply chain verification def verify_mcp_integrity(mcp_manifest): # 1. Verify MCP Manifest Signature if not ed25519_verify(mcp_manifest.signature, mcp_manifest.public_key): return {"status": "fail", "reason": "invalid_manifest_signature"} # 2. Retrieve & Verify SBOM sbom = fetch_sbom_from_sigil(mcp_manifest.sbom_hash) if not ed25519_verify(sbom.signature, sbom.signer_public_key): return {"status": "fail", "reason": "invalid_sbom_signature"} # 3. Transitive Dependency Audit for dependency in sbom.dependencies: if not is_trusted_dependency(dependency): return {"status": "fail", "reason": "untrusted_dependency"} # 4. Red-Line Policy Check (dynamic code analysis, content filtering) if contains_red_line_patterns(mcp_manifest.code_hash): return {"status": "fail", "reason": "red_line_violation"} # 5. Runtime Environment Attestation runtime_attestation = fetch_runtime_attestation(mcp_manifest.runtime_id) if not runtime_attestation.is_valid(): return {"status": "fail", "reason": "invalid_runtime_attestation"} return {"status": "pass", "message": "MCP supply chain verified."}

3. Anomaly Detection

3.1 Real-time Monitoring

The SCIS monitors MCP servers in real-time for deviations from their attested SBOMs. Any detected change, unauthorized process, or anomalous network activity triggers an alert and initiates a BFT emergency session.

3.2 Red-Line Detection

All incoming data, outgoing inferences, and internal processing are scanned for red-line policy violations (e.g., kinetic targeting patterns, personal surveillance, specific banned keywords). Immediate quarantine and alert on detection.

3.3 Threat Intelligence Feed

Integrates with UK-specific threat intelligence feeds (e.g., NCSC advisories) to proactively identify vulnerable components and zero-day exploits impacting the supply chain.

4. Response and Remediation

4.1 Quarantine Protocol

On integrity compromise, the affected MCP server is immediately quarantined, isolated from the network, and its attestations are revoked. Traffic is rerouted to a trusted, clean instance.

4.2 BFT Remediation Vote

Remediation actions (e.g., re-deployment, software updates, rollback) require a BFT council vote. This prevents unilateral changes and ensures consensus on recovery strategies.

4.3 Forensic Logging

Detailed forensic logs are generated and stored in the SIGIL ledger for post-incident analysis and compliance reporting. These logs are immutable and cryptographically verifiable.

5. Compliance Cross-Walk

Standard	Section	How SCIS Meets It
NCSC CAF	B4 (Secure by Design)	Multi-layer integrity verification, SBOMs, signed artifacts
ISO 27001	A.12 (Supply Chain Security)	Continuous monitoring, vendor assessment, incident response
UK GDPR	Article 32	Ensures integrity of systems processing personal data
DPA 2018	Schedule 1 Part 4	Protects against unauthorized modifications of processing systems
EU AI Act	Article 15 (Transparency)	Full audit trail of AI system components and data sources
NIST CSF	ID.SC (Supply Chain Risk Management)	Identifies, assesses, and manages supply chain risks

6. Production Metrics

Metric	Value
MCPs actively monitored	30
Daily integrity scans	150+
SBOMs generated / verified	90 (every build)
Red-line violations detected	0 (all blocked pre-deployment)
Compromise events	0
Verification latency (p99)	35ms
SIGIL receipts (SCIS events)	4,128