Proof slip, made on your device

Print a slip your records can be checked against.

Choose a record, a set of records, or a corrected version. This page fingerprints each one here and makes a slip to print or save. Later, anyone holding the file and the slip can check it on a phone. Nothing is uploaded.

Nothing to hand? or .

Adding to a record over time, like a carer's hours? Keep a running log.

1. The records

One file, or several in the order they happened (up to 20). Or paste text.

OR PASTE TEXT

2. On the slip

Print file names
Untick if the names say too much. The fingerprints are enough to check. A note for the slip (optional, stays on this page) This corrects an earlier version
Binds the new version to the earlier one and to the reason, so the change is on paper.

HashCare proof slip

Slip fingerprint

To check a record: scan its code, or open hashcare.com/check, choose the file and paste its fingerprint. Matching fingerprints mean identical bytes. They do not say the record is true, complete, or signed by anyone. A re-saved or scanned copy gets a new fingerprint.

Anchor the slip fingerprint

Anchoring is optional and permanent: it puts only the slip fingerprint and a time in the public registry, after you press Anchor on the next page.

One recordThe slip shows its SHA-256. Check the file against it at /check.

A setEach record keeps its own fingerprint and code. The slip fingerprint covers the whole list in order, so a missing or swapped record shows.

A correctionA five-line text names the earlier fingerprint, the new one, the reason's fingerprint and the date. The slip fingerprint is that text's SHA-256, and the text is printed so anyone can recompute it.

If someone is in danger right now, call 911. If you are in crisis, call or text 988.