V13-B Design Plan

SafeGate V13-B External Anchor Design Plan

V13-A closed the public evidence chain for proof-record inclusion and signed checkpoint consistency. V13-B defines the next boundary: external anchoring through Bitcoin/OpenTimestamps as timestamp infrastructure, not as a payment rail.

V13-A Chain

CLOSED

V13-B Design

OPEN

V13-B Checklist

OPEN

Production Claim

FALSE

Open V13-B Implementation Checklist Open Technical Evidence Archive Open Pilot Review Index Open Roadmap

1. Core Boundary

SafeGate does not process payments, hold funds, custody assets, escrow value, route payments, or exchange funds. SafeGate verifies what happened after payment.

V13-B rule: Payment rail is separate from anchor rail.

Bitcoin/OpenTimestamps boundary: Bitcoin/OpenTimestamps are used only as external timestamp / anchor infrastructure. This does not mean Bitcoin payment support is live.

2. What V13-A Closed

Proof-record inclusion and signed checkpoint consistency.
Append-only transparency log direction.
Canonical leaf hash direction.
Merkle inclusion proof direction.
Independent browser verifier.
Anchor negative test: unsupported anchor claims do not become verified anchors.
Technical Evidence Archive, Roadmap, Checklist, Freeze Note, and main landing linkage.

Important: V13-A does not prove independent payment truth, does not claim live external anchoring, and does not claim production readiness.

3. What V13-B Opens

V13-B defines how a SafeGate signed checkpoint can be externally anchored to an independent timestamp layer. The goal is to make the proof timeline harder to rewrite after publication.

Define checkpoint commitment format.
Define external timestamp proof attachment format.
Define verifier anchor states.
Require pinned or well-known public key direction.
Keep payment truth separate from proof integrity.
Keep Bitcoin/OpenTimestamps as anchor infrastructure only.

Implementation checklist: The V13-B implementation checklist is now open as a separate public-safe page.

Open V13-B External Anchor Implementation Checklist

4. Payment Rail vs Anchor Rail

Payment rail

The rail that confirms whether a buyer paid through Pi, stablecoin, crypto, Bitcoin, Ethereum, Solana, card, bank, or local fiat adapter.

Anchor rail

The independent timestamp layer used to anchor a SafeGate checkpoint after the proof record exists. In V13-B, Bitcoin/OpenTimestamps belong here only.

Boundary: A Bitcoin/OpenTimestamps anchor does not mean Bitcoin payment support is live. It only means SafeGate is designing an external timestamp anchor path for signed checkpoints.

5. Anchor State Model

V13-B must avoid the main overclaim risk: treating a claimed anchor field as a verified anchor. The verifier must parse anchor status conservatively.

{
  "anchor_pending": "No external timestamp proof is attached yet.",
  "anchor_unsupported": "The proof claims an anchor type that this verifier does not verify.",
  "anchor_claim_unverified": "The proof contains an anchor claim, but verification was not completed.",
  "anchor_verified": "The external timestamp proof verifies against the checkpoint commitment.",
  "anchor_mismatch": "The anchor proof does not match the checkpoint commitment.",
  "anchor_error": "The anchor proof could not be evaluated safely."
}

Fail-secure rule: Unknown, unsupported, malformed, mismatched, or ambiguous anchor evidence must never be displayed as verified.

6. Public Key Pinning Requirement

The verifier must not blindly trust a public key embedded inside the proof. V13-B should be designed with a pinned or well-known public key path.

/.well-known/safegate-log-key.json

{
  "product": "SafeGate",
  "purpose": "transparency-log-checkpoint-verification",
  "environment": "staging",
  "keyId": "safegate-v13-staging-log-key-001",
  "algorithm": "Ed25519",
  "status": "active",
  "publicKey": "PUBLIC_KEY_PLACEHOLDER"
}

Status: This is a design and implementation-readiness requirement. It is not a production key pinning completion claim.

7. V13-B Acceptance Criteria

External anchor design plan is public.
External anchor implementation checklist is public.
Payment rail and anchor rail are explicitly separated.
Bitcoin/OpenTimestamps are described only as timestamp infrastructure.
Anchor states are fail-secure.
Unsupported anchor claims cannot self-upgrade into verified status.
Pinned / well-known public key requirement is documented.
No production anchor claim is made.
No Bitcoin payment adapter claim is made.

8. Not Claimed

Not production ready.
Not formally audited.
No live external anchor claim yet.
No independent payment truth proof claim yet.
No Bitcoin payment adapter live claim.
No stablecoin adapter live claim.
No fiat/bank/card adapter live claim.
Not a payment processor, custodian, escrow provider, exchange, wallet holder, or settlement network.

9. Related Evidence Pages

Main Landing V13-B Implementation Checklist V13 Proof Integrity / Anchor Design V13-A Checklist V13-A r1 Freeze Note Independent Verifier Technical Evidence Archive Pilot Review Index Roadmap

10. Machine-Readable Status

{
  "project": "SafeGate",
  "page": "v13-b-external-anchor-design-plan.html",
  "status": "V13_B_DESIGN_PLAN_UPDATED_WITH_IMPLEMENTATION_CHECKLIST",
  "v13AChain": "CLOSED",
  "v13BDesignPlan": "OPEN",
  "v13BImplementationChecklist": "OPEN",
  "externalAnchorLive": false,
  "productionAnchorClaim": false,
  "formalAuditClaim": false,
  "bitcoinPaymentAdapterLive": false,
  "bitcoinUsedAs": "external_timestamp_anchor_only",
  "openTimestampsRole": "candidate_external_timestamp_proof_layer",
  "paymentRailSeparatedFromAnchorRail": true,
  "paymentTruthDeferredTo": "V13-C Payment Commitment",
  "pinnedPublicKeyRequired": true,
  "verifierMustFailSecure": true,
  "safeGatePaymentProcessor": false,
  "safeGateCustody": false,
  "safeGateEscrow": false,
  "safeGateExchange": false,
  "safeGateWalletHolder": false
}