What is a digital signatureA cryptographic check that a file came from the holder of a key and has not changed since signing

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

A digital signature is a cryptographic value, made with a private key, that lets anyone with the matching public key check who signed a file and that it has not changed since. It is not the same as a scanned or typed signature, and its value depends on how the key was issued.

How it works

The file is hashed, and the hash is signed with the signer’s private key. A recipient checks it with the public key. If the file changes by one byte, the check fails. See the glossary entry.

An “electronic signature” is a broader legal term that can include a typed name or a drawn mark. A digital signature is one technical method and may be used within an electronic signature. How either is treated in law depends on the country and the document, so ask a lawyer where it matters.

Digital signature and a timestamp

A signature ties a file to a key holder. It does not by itself prove when it was signed unless a trusted time source is included. A TimeBind records a SHA-256 fingerprint of the exact file and a time, anchored to Bitcoin. The fingerprint is made in your browser and the file is not uploaded. A TimeBind adds an independently checkable time for the file.

A TimeBind is not a digital signature and does not identify who made the file.

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 a digital signature the same as an electronic signature?

No. An electronic signature is any electronic mark of agreement. A digital signature is a cryptographic method that can be used for one.

Does a digital signature prove the date?

Not by itself. The date needs a trusted timestamp.

Is a digital signature legally binding?

It depends on the country and document type. Ask a lawyer.

Can a digital signature be forged?

Forging one without the private key is not known to be practical, but a stolen or poorly issued key undermines it.

Sources

NIST, Glossary: digital signature.
TimeBinder, Glossary.

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

Record a fingerprint of the file you rely on

Add a layer of protection against AI and human fraud and disputes: a dated, checkable record of the exact file you hold.

Open the app and sign in with email or Google.
Add your files. They stay on your computer.
Seal them and download your Proof of Time certificates.

Open TimeBinder →

First Pooled TimeBind free, no card, then from US$5. See pricing.