Live demo · Patent pending · No account
Somewhere between the moment a payment is approved and the moment it executes, the instruction can be changed, replayed, or answered by a different model than the one that was reviewed. You pick the attack. We run it twice, once with nothing watching and once with the gateway on.
This demo proves custody of the instruction. The value that executes is the value that was approved, by the party that was approved, inside the window that was approved.
It does not prove the answer was right, and it does not prove any model was honest. No receipt can do that, and we are not going to pretend otherwise.
One ordinary payment. A controller approves it, a model reviews the approval, and a payment service executes it a few seconds later somewhere else.
Each one happens after approval and before execution. Nobody has to break into the approver's account for any of them.
The payment service did its job. It executed the instruction it received, and it wrote that instruction into the audit log.
The log is not wrong on purpose. It only ever saw the instruction that arrived. There is nothing in it to compare against, so a changed value and an approved value look identical after the fact.
At approval time the gateway takes a digest of the exact instruction, the approver, the reviewing model and the approval window, and keeps it. That digest is the commitment.
At arrival it takes the digest again and compares. If any bound field moved, the comparison fails, the gateway names the field that moved, and execution refuses. No judgement about whether the payment was a good idea. Only whether it is the one that was approved.
Every digest on this page is computed in your browser with SHA-256 through the standard Web Crypto interface. Nothing is sent anywhere, and the page keeps working with the network off. Open your developer tools and watch it if you want to.
The signature in the receipt below is produced by a demo key generated in your browser for this session only. It is labelled as such in the receipt. It is not the Hive production signer, which signs ML-DSA-65 under NIST FIPS 204, and it is not a countersignature.
A record signed only by the party that produced it answers a narrower question than most people assume. It shows the instruction did not change in custody. It does not settle a dispute where the operator itself is the party in question, because the operator picked the timestamp and holds the only copy.
Closing that needs a second signing party with its own key, its own clock, and an append-only log you can check without asking the operator for anything. We built that service and it signs real records. Today Hive runs it, so it is a second key rather than an outside party, and its own health endpoint reports that in plain words. We will say it is independent when it runs somewhere we do not control, and not before.
Check a receipt yourself with no account, read how the gateway sits in front of your own traffic, or tell us what you are trying to prove.