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The CertNode primitive

Cryptographic proof for events that get challenged later.

CertNode is a cryptographic-proof company. One primitive — a signature, an independent timestamp, and a Bitcoin anchor — produces a tamper-evident, independently verifiable record. Every product on this site is that same primitive applied to a moment someone may later dispute.

Signature
ES256 / HMAC
Independent time
RFC 3161
Anchor
Bitcoin
In plain terms

CertNode turns a moment that matters — a payment, an agreement, an AI output, a shipment — into a receipt that is three things at once: tamper-proof (change one detail and it visibly breaks), independently dated (no one can backdate it), and checkable by anyone (they verify it themselves — they do not have to trust you).

So when someone disputes what happened months later — a customer, their bank, an auditor, opposing counsel — the receipt settles it instead of your word against theirs. The cryptography below is how it holds up; you do not need to understand it to use it.

Three layers, one record

Each layer answers a question a hostile party will ask later: who signed it, when did it exist, and can the date be revoked?

LAYER 1

Signature layer

A cryptographic signature over the content hash — an ES256 (ECDSA P-256) signature on AI-Provenance receipts, and an HMAC-SHA256 integrity seal on commerce records. Change one byte of the record and it no longer validates — that is what makes it tamper-evident.

LAYER 2

RFC 3161 timestamp

An independent Time Stamp Authority countersigns the hash — the standard cryptographic timestamp format cited in case law. It establishes when the record existed without relying on our word or your account.

LAYER 3

Bitcoin anchor

The hash is anchored to the Bitcoin blockchain via OpenTimestamps — a non-revocable proof of pre-existence that no party, including us, can later forge or roll back.

Together the three layers form a record structured to the FRE 902(13)/(14) self-authenticating standard for electronic evidence — built so its integrity and date can be established without a foundation witness.

Records link into a chain

Each receipt can reference its parents, so a sequence of related events — an order, its payment, the shipment, the delivery — becomes one tamper-evident chain. Modify any link and every signature downstream breaks.

Because the structure is a graph, a single sub-chain can be verified on its own without loading everything else — the part you need to prove, and nothing more.

1
Order receipt
depth 0 · parents: none
2
Payment receipt
depth 1 · parent: order
3
Shipment receipt
depth 2 · parent: payment
4
Delivery receipt
depth 3 · parent: shipment

Verify it independently — not just on our word

Every receipt has a public verification page that re-checks each layer in the browser — no account needed. The independent anchors do the heavy lifting: the RFC 3161 timestamp checks against the Time Stamp Authority (FreeTSA) and the Bitcoin anchor against the blockchain, neither of which we control. On AI-Provenance receipts the ES256 signature is additionally checkable against our published public key.

AI-Provenance verification — Node.js
import { createHash, createVerify } from 'crypto'

// Verify an AI-Provenance receipt against our public verify endpoint —
// the ES256 signature is checkable against the published public key.
function verifyReceipt(receipt, publicKeyPem) {
  // 1. Recompute the content hash
  const hash = createHash('sha256')
    .update(receipt.canonicalPayload)
    .digest('hex')
  if (hash !== receipt.data_hash) return false

  // 2. Verify the ES256 signature against the published public key
  const v = createVerify('SHA256')
  v.update(receipt.data_hash)
  return v.verify(publicKeyPem, receipt.signature, 'base64')
}

Start where the proof already pays off.

The warmest line is chargeback defense — a proven category, priced so you only pay when it wins.

The CertNode cryptographic-proof platform | CertNode