What is blockchain timestamping?A fingerprint plus a time, recorded on a public chain

TimeBinder adds a layer of protection against AI and human fraud and disputes.

The file stays on your device. Your browser makes a digital fingerprint of the file. TimeBinder records the fingerprint and the time, not the file.

Short answer

Blockchain timestamping records a fingerprint of a file, not the file, in a chain such as Bitcoin. A later check can show that exact file existed no later than the block time and still matches. It does not show who made the file, that the contents are true, or that you own the rights.

How a blockchain timestamp is made

The usual steps are the same whether you use OpenTimestamps, a TimeBind, or a similar service. Software computes a SHA-256 hash of the exact bytes of the file. That fingerprint is often combined with others in a Merkle tree, and a short value is written into a Bitcoin transaction. Later, anyone with the file and the proof can recompute the hash and follow the path to a real block. The file itself is not stored on the chain. See what a Bitcoin file timestamp contains and how blockchain timestamping works.

A TimeBind does this in the browser: the fingerprint is made on your device, the file is not uploaded, and the record is anchored to Bitcoin. The first Pooled TimeBind is free, then from US$5; an ASAP TimeBind is US$15. OpenTimestamps is a free, open-source way to do a similar job, usually from the command line; see alternatives to OpenTimestamps and free blockchain timestamping compared.

This is different from a notary confirming who signed, and from an RFC 3161 trusted timestamp issued by a timestamp authority. See hash timestamps versus notarisation and RFC 3161 versus a blockchain timestamp.

What it shows, and what it does not

A matching file plus a valid proof shows that those exact bytes existed no later than the time of the block, and that the file you hold now is the same. It does not show authorship, ownership, copyright, or that the contents are true. A later edit produces a different fingerprint and needs its own record. Block times are not a stopwatch: they are reliable to within a couple of hours, not to the second, so this suits questions measured in days, months or years.

Make a TimeBind: first one free →

First Pooled TimeBind free, no card, then from US$5. An ASAP TimeBind is US$15.

Frequently asked questions

Is the file uploaded to the blockchain?

No. Only a fingerprint (and a short combined value derived from it) is recorded. With a TimeBind, the SHA-256 fingerprint is made in your browser and the file stays on your device.

Does a blockchain timestamp prove I made the file?

No. It shows that this exact file existed no later than the recorded time and still matches. It does not show who created it, who owns it, or that you have any legal right in it.

How is this different from a notary?

A notary typically identifies a person and witnesses a signature. A hash timestamp does not identify anyone. It dates the bytes of a file. See hash timestamp versus notarisation.

How precise is the time?

A Bitcoin block time is reliable to within a couple of hours, not to the second. Use it for questions measured in days, months or years, not for a claim about a particular minute.

Sources

OpenTimestamps, opentimestamps.org (open calendar protocol anchoring hashes in Bitcoin).
Bitcoin, developer reference on the block chain and headers.
TimeBinder, A Bitcoin timestamp proof, explained.

Related guides and tools

Your file’s fingerprint, anchored to a global network secured by real electricity and cryptography.

Editing a file—including with AI—changes its fingerprint, not its existing network record.

How this works

Your file’s SHA-256 fingerprint, a short code worked out from its exact contents, is made in your browser, and the file itself stays on your device. A cryptographic commitment to that fingerprint, which may be combined with others, is then anchored in a block on the Bitcoin blockchain. Bitcoin is secured by proof of work: computers around the world spend real electricity to add each block, and changing an earlier block would mean redoing that work faster than the rest of the network. Until that block is confirmed, your proof is pending. Once the Bitcoin anchoring is confirmed, you can verify the proof against that recorded commitment. The confirmed record can then be checked; Pooled TimeBinds are checked through TimeBinder, while ASAP TimeBinds can also be checked independently. If you check the file later and its fingerprint still matches, that shows the file existed no later than the recorded time. The record doesn’t show who made the file, whether AI was used, or that its contents are true.

Your filestays on your device
FingerprintSHA-256
Network timestampon Bitcoin

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Related glossary entries: proof of work, Bitcoin node and block height.