Vulnerability disclosure & security posture.

Report a vulnerability.

• Primary channelEmail security@epochpay.today. Same-day acknowledgment during US business hours; within 24 hours otherwise.
• Encrypted attachmentsPGP key fingerprint and ASCII-armored public key published at /.well-known/security.txt (forthcoming) — until that's live, encrypted attachments via age or signed Keybase chat acceptable on request.
• Triage SLACritical (active exploitation, key disclosure): 24 hours · High (auth bypass, signature forgery): 72 hours · Medium / Low: 5 business days.
• Coordinated disclosure90-day default disclosure window from triage date; extensions on agreement for vendor-side coordination. Researchers credited in /trust hall-of-fame on request.
• Safe harborGood-faith research within stated scope is authorized and will not result in legal action by EpochCore LLC.

Scope.

Threat model summary.

• Receipt forgeryAn attacker forges a receipt that /verify accepts. Mitigation: every receipt carries an ML-DSA-65 signature (NIST FIPS 204) over the canonical receipt hash. Public key fingerprint at /v1/pay/pubkey; rotation is logged in the WORM chain.
• Chain rewriteAn attacker silently rewrites a past WORM entry. Mitigation: every entry chains to the prior via triple-hash (SHA-256 + SHA3-512 + BLAKE3); chain head at /v1/waterseal is publicly verifiable.
• UI tamperingAn attacker changes a number on a public page (compliance claim, retention period, fee). Mitigation: every public page is captured nightly via Cloudflare Browser Rendering and sealed (pixelHash + blake3 + sha3-512 + ed25519). Snapshots at /snapshots.
• Supply-chain compromiseA dependency or sub-processor is compromised. Mitigation: /trust/regulatory lists every sub-processor; build receipts seal the exact code that was deployed; D1 + R2 are managed by Cloudflare with their own SOC 2 / ISO posture.
• Key compromiseThe ML-DSA-65 service key is exfiltrated. Mitigation: key rotation logged in the WORM chain; older keys remain verifiable for historical receipts; rotation rehearsal in 2026-Q3 roadmap.
• Post-quantum riskAn attacker with a future quantum computer breaks classical signatures retroactively. Mitigation: receipts are signed post-quantum by default (ML-DSA-65 / FIPS 204); classical-only signing is not in any code path.

Cryptographic substrate.

• Signature schemeML-DSA-65 (NIST FIPS 204). Implementation via @noble/post-quantum.
• Content hashSHA-256 of canonical-JSON receipt payload (RFC 8785).
• WORM chain hashSHA-256 + SHA3-512 + BLAKE3 (triple-hash) of {prev_seal_hash, content_hash, ts, idx}.
• Public verifier/verify accepts pasted intent + receipt JSON and returns the verification result + chain link with no API key required.
• Snapshot sealpixelHash (pHash of the rendered image) + blake3 + sha3-512 + Ed25519 signature over the canonical seal envelope.

Supply chain.

• RuntimeCloudflare Workers (V8 isolates, no VMs). D1 (SQLite) for merchants + intents. R2 for receipt envelopes. KV for state + status checks.
• DependenciesOne production dependency: @noble/post-quantum (audited TypeScript). Build-receipt seals the exact dependency tree per deploy.
• Sub-processorsSee /trust/regulatory for the full list.

Disclosure history.

No public disclosures to date. As reports come in and are remediated, they'll be listed here (date, category, credit if requested).

Want a deeper conversation?

Security review for procurement / compliance: email trust@epochpay.today. SOC 2 bridge letter available on request; Type II report target Q4 2026 (see /trust for the full posture).