What is a Merkle treeA structure that combines many hashes into one root hash, so one value can stand for a large set of data

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 Merkle tree is a way to combine many hashes into a single root hash. Each pair of hashes is hashed together, level by level, until one value remains. Changing any item changes the root, and a short path of hashes can show an item is included. Bitcoin uses them for transactions.

How the tree is built

Each file or record is hashed to make a leaf. Leaves are paired and hashed together, then those results are paired again, until one root hash is left. The idea is named after Ralph Merkle. See the glossary entry.

To show that one item is in the set, you give its hash and the few sibling hashes along the path to the root. Anyone can recompute the root and compare. Bitcoin’s design uses a Merkle tree to summarise the transactions in each block (Bitcoin white paper).

Why it matters for timestamping

Merkle trees let many fingerprints share one anchoring step instead of needing a separate transaction each. 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. See what is blockchain timestamping.

The tree shows inclusion and unchanged data. It does not show the data is true or who created it.

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

What is the Merkle root?

The single hash at the top of the tree. Changing any leaf changes it.

Why not hash everything together at once?

A tree lets you prove one item belongs with a short path, without handing over all the other data.

Does Bitcoin use Merkle trees?

Yes. Each block summarises its transactions with a Merkle root.

Is a Merkle tree encryption?

No. It is built from hashes, which are one-way and use no key.

Sources

Satoshi Nakamoto, Bitcoin: A Peer-to-Peer Electronic Cash System.
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.

Related glossary entries: block header, nonce and preimage resistance.