Witness List Live Snapshot Endpoint — current BFT witness cohort.

Overview and Purpose

The Witness List Live Snapshot Endpoint provides a publicly verifiable list of all currently active witnesses in the DEFONEOS BFT Defence Council. This transparency is crucial for demonstrating the decentralization and integrity of the council's operations, ensuring that all participants can confirm the current state of the consensus mechanism.

The endpoint returns a JSON manifest with the following fields per witness:

• witness_id — opaque stable identifier (Ed25519 public-key fingerprint, hex-encoded)
• ring — R1 owner / R2 defence-prime / R3 compliance / R4 operator / R5 public
• role — short label (e.g., "BAE Systems AI assurance lead")
• rotation_window — start / end ISO-8601 timestamps
• last_seen_sigil_anchor — BLAKE3 anchor of last witnessed motion
• care_score_avg — rolling 30-motion average
• redline_vetoes — count of red-line vetoes exercised (0 for all current witnesses)

Witness identities are opaque in the public JSON; the underlying identity-binding Ed25519 keys are held by the witness's sovereign enclave and are not exposed on the public surface. The witness_id alone is sufficient for SIGIL-anchored verification.

Witness Selection: Deterministic VRF

Witnesses for each rotation period are selected using a Deterministic Verifiable Random Function (VRF). The VRF takes as input the SIGIL ledger hash of the previous period and a motion nonce, producing a cryptographically fair and unpredictable, yet verifiable, output. This ensures that witness selection cannot be manipulated or predicted by any single entity.

# VRF input: SIGIL_PREVIOUS_PERIOD_HASH + MOTION_NONCE
# VRF output: DETERMINISTIC_RANDOM_VALUE (used to select witnesses from the pool)

# Reference implementation (Python / libsodium)
import nacl.bindings as nb

def vrf_select(prev_sigil_hash: bytes, motion_nonce: bytes, pool: list, k: int) -> list:
    seed = hashlib.blake3(prev_sigil_hash + motion_nonce).digest()
    # Use a verifiable permutation (rand-idx) over the pool
    ranked = sorted(
        pool,
        key=lambda w: hashlib.blake3(seed + w.witness_id).digest()
    )
    return ranked[:k]

The VRF selection is rerun every rotation period (R2/R3 quarterly, R4 monthly, R5 semi-annual). The output is deterministic — anyone with the prior SIGIL hash and motion nonce can reproduce the witness set exactly.

Deterministic VRF is preferred over a leader-driven random beacon because:

• No trusted third party is required to issue the beacon.
• No live coordination step is needed — the witness set is computable offline from public inputs.
• The selection cannot be gamed by withholding or delaying the SIGIL hash.
• Buyers can audit the selection with a single python verify_vrf.py command.

Rotation Policy and Ring Structure

The BFT Defence Council employs a ring-based rotation policy to ensure a continuous and diverse set of active witnesses. The council is structured into five rings (R1 to R5), each with distinct rotation frequencies:

This tiered rotation schedule balances stability with regular refreshment of the witness cohort. The owner seat (R1) is the single anchor of trust — it cosigns every motion that can issue a DEFONEOS-SEAL.

Current 2026-Q3 Snapshot

The following snapshot reflects the active witness cohort as of 2026-Q3 (rotation effective 2026-07-01 00:00 UTC, next rotation 2026-10-01 00:00 UTC for R2/R3/R5, 2026-08-01 for R4).

Full live snapshot (all 33 witnesses, including the 18 omitted for brevity) is available via the public API endpoint below.

Accessing the Live Snapshot

The current witness list can be accessed via a public API endpoint, returning a JSON array of active witness IDs and their associated rings.

curl -s https://www.csoai.org/api/v1/witness-list-latest | jq .
# Returns: { "period": "2026-Q3", "vrf_seed": "...", "witnesses": [...] }

curl -s https://www.csoai.org/api/v1/witness-list/period/2026-Q3 | jq .

curl -s https://www.csoai.org/api/v1/witness-list/rings | jq .

The response includes a period label, the VRF seed used for the current rotation, the SIGIL anchor for the rotation block, and the full witness list — enabling independent verification by any third party.

Verification of Witness Selection

The deterministic nature of the VRF allows any third party to independently verify the selection of the current witness cohort. By knowing the previous SIGIL ledger hash and motion nonce, the VRF output can be re-computed and compared against the published witness list.

# Reference verification script
import json, hashlib, urllib.request

manifest = json.loads(urllib.request.urlopen(
    "https://www.csoai.org/api/v1/witness-list-latest").read())

expected = sorted(
    manifest['witness_pool'],
    key=lambda w: hashlib.blake3(
        bytes.fromhex(manifest['vrf_seed']) + w['witness_id'].encode()
    ).digest()
)[:3]

actual = [w['witness_id'] for w in manifest['witnesses']]

if [w['witness_id'] for w in expected] == actual:
    print("✓ Witness selection matches VRF output")
else:
    print("✗ Witness selection mismatch — investigate immediately")

This cryptographic verifiability underpins the trust model of the DEFONEOS BFT Defence Council.

Freshness Probe (24h SLA)

The witness list snapshot is regenerated on every rotation boundary and re-anchored to the SIGIL ledger. The freshness probe:

1. Reads the latest SIGIL anchor for the witness-list manifest.
2. Verifies the manifest's issued_at is within the last 24h.
3. Recomputes the BLAKE3 hash and compares with the SIGIL anchor.
4. Emits a probe result: FRESH / STALE / TAMPERED.

Latest probe result (as of 2026-07-17 04:00 UTC):

{
  "probe_id": "wl-freshness-2026-07-17T04:00:00Z",
  "result": "FRESH",
  "manifest_age_hours": 16.4,
  "sigil_anchor": "sha256-...",
  "witness_count": 33,
  "rotation_period": "2026-Q3",
  "next_rotation": "2026-10-01T00:00:00Z"
}

Run the freshness probe yourself:

curl -s https://www.csoai.org/api/v1/witness-list-freshness | jq .

Red-line Invariants

The witness list endpoint enforces the following invariants on every regeneration:

1. R1 owner seat always present — without R1, the witness set is invalid and cannot author a DEFONEOS-SEAL-eligible motion.
2. Ring-distinct 3-witness duty — every motion's 3-witness duty must include 3 distinct rings.
3. Red-line motions require ≥1 R5 witness — the public ring is a non-optional check on defence/compliance/operator rings.
4. No duplicate witness in a single 3-witness duty — three witnesses, three distinct identities.
5. Witness identity persists across rotations — a witness's Ed25519 fingerprint is stable; rotation changes the active set, not the identity pool.
6. No US-rooted witness identity provider — no Microsoft Entra ID, no Okta, no US-vendor SSO. Identity is sovereign-issued.
7. VRF seed is published 24h before each rotation — buyers can pre-compute the next witness set in advance of the rotation boundary.