Proof

A record nobody can quietly rewrite. Including us.

Sealed in your browser, verifiable by anyone, readable only by you. One engine for consent, handovers, inspections, screenings and doors.

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Try to change the record

  1. #41 · Consent wording v3hash …
  2. #42 · Patient signaturehash …
  3. #43 · Sealed receiptcovers #42 · signed

Checking the chain…

A toy, worked in your browser with real SHA-256: each entry is hashed with the one before it, so changing one breaks every link after it. The real thing, with signed receipts, is the Evidence Chain demo.

How it works

Three steps, the same in every use.

  1. 1

    Seal

    The record is encrypted in your browser and kept in the Vault. The key never leaves you.

    vaultPut(…)
  2. 2

    Receipt

    Only its hash goes to Attest, which orders it, signs it and chains it to the one before.

    attest({ contentHash })
  3. 3

    Verify

    Anyone re-derives the chain and checks every signature against the published key, without asking the platform.

    attestVerify(…)
See the mechanism in the Evidence Chain demo →

Five uses

Pick the one that is yours.

Consent · clinics

Signet

Informed consent on the patient's own phone, sealed before treatment.

Sealed
wording, answers, both signatures
Who confirms
patient, clinician
Priced
per clinician
Open Signet

Handover · care homes

Baton

Every item acknowledged by name; critical ones block close-out.

Sealed
the board, acknowledgements
Who confirms
each person taking over
Priced
per home
Open Baton

Inspection · insurers

Fieldstamp

The inspector stays put; a phone camera shows the site, logged as it happens.

Sealed
photos, hashed on the phone
Who confirms
the inspector
Priced
per completed inspection
Open Fieldstamp

Screening · edit bays

Screener

Stream a cut from the edit bay; approval signed against the exact file.

Sealed
the file hash, notes, approval
Who confirms
the client
Priced
per screening room
Open Screener

Doors · events

Turnstile

Any phone is a scanner; the gates keep admitting when the network dies.

Sealed
every admission, every collision
Who confirms
each gate
Priced
per event
Open Turnstile

Something else to prove?

The same engine fits any record that must not change after the fact.

Talk to us

Trust

What we can see, and what we cannot.

That a record exists, when it was sealed, and the hash that pins it.

The record itself. It is encrypted before it leaves your browser.

What if the key is lost?

Then nobody can read the record, including us. The receipt still proves it existed and was not changed.

Does verifying need your servers?

No. Verification re-derives every hash and checks every signature against the published key. It never asks the platform whether the platform is honest.

Can two people append at once?

Yes. Attest locks the head of the chain before it numbers an entry, so a second writer waits its turn rather than racing; every entry gets one place in one order.

Licensed per use, priced for the job.

Commercial — licensed per use, priced for the job: per clinician, per home, per completed inspection, per screening room, per event.

Talk to us