How does blockchain timestamping work?
Discover how LegalStamp uses the Bitcoin blockchain to create irrefutable proofs of existence for your documents.
Steps
Drop your file
Drag and drop your document into the interface. The file stays on your computer and is never uploaded to our servers.
Fingerprint calculation
The SHA-256 fingerprint (hash) of your file is calculated locally in your browser. This unique fingerprint identifies your document in an unfalsifiable way.
Blockchain anchoring
The fingerprint is submitted to the OpenTimestamps protocol which anchors it in the Bitcoin blockchain, creating an immutable timestamped proof.
Proof certificate
You receive a PDF certificate and an .ots file that constitutes the cryptographic proof. These documents can be verified by anyone, at any time.
Use cases
Blockchain timestamping is useful in many professional and personal contexts.
Intellectual property
Prove the creation date of your works, designs, inventions, or ideas.
Legal compliance
Demonstrate the existence date of legal and contractual documents.
Business data
Establish proof of priority for your strategic data.
Digital evidence
Certify the authenticity of digital content at a specific date.
OpenTimestamps Technology
OpenTimestamps is an open source protocol developed by Peter Todd, a major contributor to Bitcoin Core. It allows anchoring timestamp proofs in the Bitcoin blockchain efficiently and economically.
Unlike centralized timestamping services, OpenTimestamps offers cryptographic proof verifiable by anyone, without depending on a trusted third party.
Learn more about OpenTimestampsAssuming target filename is 'document.pdf'
Success! Bitcoin block 123456 attests
document.pdf existed as of 2024-01-15
Frequently asked questions
How does OpenTimestamps work?
OpenTimestamps is an open source protocol that aggregates multiple document fingerprints, calculates a Merkle tree, and anchors the root of this tree in a Bitcoin transaction. This proves that a document existed at the time of the Bitcoin block creation.
Is the proof legally valid?
Blockchain timestamping constitutes robust technical proof of a document's existence at a given date. Its evidentiary value depends on the jurisdiction and context, but it is increasingly recognized by courts as evidence.
What happens if I lose my original file?
Without the original file, you cannot prove that you are the holder. We only store the fingerprint (hash) of your file. It is therefore essential to keep a secure copy of your timestamped files.
How long is the proof valid?
The proof is permanently anchored in the Bitcoin blockchain and remains valid as long as the blockchain exists. For free accounts, we retain metadata for 1 year. Solo, Pro and Team plans benefit from permanent retention.
Are my files confidential?
Absolutely. Your files never leave your browser. Only the SHA-256 fingerprint (a 64-character string) is sent to our servers. This fingerprint cannot be used to reconstruct the file content.