Helm — Post-Quantum Attestation & Policy Engine

"The Mandalorian without Helm is just a dangerous phone."

---

Purpose

Helm is the security policy and attestation layer of the Mandalorian system. While the Mandalorian Gate enforces individual capability checks, Helm:

1. Issues capabilities to agents (post-quantum signatures)
2. Evaluates dynamic policy at gate time (can revoke capabilities in real-time)
3. Maintains the audit log (receipt aggregation, threat signal correlation)
4. Performs attestation — proves to external parties what software is running

---

Architecture

Helm
├── Attestation Module    — Post-quantum key management + measurements
│   ├── CRYSTALS-Dilithium (ML-DSA) — quantum-resistant identities
│   └── Ed25519 — classical fallback
│
├── Capability Issuer     — Generates signed capability tokens
│   ├── Capability schema (schema.h)
│   ├── Issuer logic (issuer.c)
│   └── Renewal / revocation
│
├── Policy Engine         — Dynamic security policy evaluation
│   ├── Policy store (policy.c)
│   ├── Threat signal integration
│   └── Real-time revocation
│
└── Monitoring            — Receipt aggregation + anomaly detection
    ├── Receipt collector
    ├── Log shipper (→ Shield Ledger)
    └── Anomaly scorer

---

Post-Quantum Identity

Helm uses compound signatures — every capability is signed by both:

typedef struct {
    // Classical: Ed25519 (fast, well-audited)
    ed25519_signature_t ed25519_sig;
    uint8_t ed25519_pubkey[32];

    // Post-quantum: CRYSTALS-Dilithium (ML-DSA-65)
    dilithium_signature_t dilithium_sig;
    uint8_t dilithium_pubkey[32];

    // Compound: both must verify for cap to be valid
} helm_compound_identity_t;

This means: - Today: Ed25519 verifies fast, Dilithium adds ~2ms overhead - After quantum: Dilithium holds; Ed25519 becomes breakable but is backed by Dilithium

---

Capability Issuance Flow

Agent requests cap
        │
        ▼
Helm verifies agent identity
  (Dilithium + Ed25519 compound sig)
        │
        ▼
Helm checks policy: "Is agent allowed this action?"
        │
        ▼
Helm generates capability:
  - Secret (HMAC key for gate verification)
  - Actions bitmap
  - Resource pattern
  - Expiry timestamp
  - Rate limits
  - Constraints
        │
        ▼
Helm signs capability (compound sig)
        │
        ▼
Capability returned to agent
        │
        ▼
Agent presents cap to Mandalorian Gate

---

Dynamic Policy

Static capabilities are insufficient — if a threat signal fires (e.g., anomalous exec pattern detected), Helm can revoke a capability before it expires:

int helm_revoke_capability(uint32_t cap_id, revocation_reason_t reason);

Revocation is: 1. Written to the policy store 2. Propagated to the Mandalorian Gate's in-memory deny list 3. Logged to Shield Ledger 4. Emitted as an anomaly event to Aegis

---

Attestation

External parties (e.g., another device, a server) can request Helm's attestation quote:

int helm_attest(
    const uint8_t *challenge,    // External nonce
    helm_quote_t *quote_out      // Signed measurement + nonce + timestamp
);

The quote contains: - PCR banks — BIOS, bootloader, kernel, device tree measurements - HMAC state — Current gate configuration - Nonce — Prevents replay attacks - Timestamp — Prevents stale quote attacks - Compound signature — Both Dilithium + Ed25519

---

Integration with Mandalorian Gate

The Gate calls Helm at Step 8 (Policy Check):

// gate.c — Step 8
if (!helm_policy_evaluate(req, cap)) {
    return GATE_POLICY_DENY;
}

And every receipt goes to Helm for audit:

// gate.c — Step 10
submit_receipt_to_helm(&receipt);

---

Security Properties

Property	Mechanism
Quantum-resistant identity	Dilithium ML-DSA-65
No capability forgeries	Compound signature (Ed25519 + Dilithium)
Real-time revocation	Policy engine updates gate deny list
Tamper-evident audit	All receipts forwarded to Shield Ledger
Secure provisioning	Out-of-band initial key exchange

---

Files

File	Role
helm/include/helm.h	Public API + data structures
helm/src/helm.c	CLI, init, emergency halt, version, config
helm/src/attestation.c	Nonce generation, hardware integrity, Dilithium + Ed25519 compound signatures
helm/src/capability.c	Capability issuance, renewal, revocation
helm/src/monitoring.c	Receipt collection, anomaly scoring, metric registration
helm/demo_helm.c	Usage demonstration

---

Helm watches. Helm attests. Helm revokes.