Notarize your documents on the Bitcoin blockchain

Blockchain notarization (often referred to as proof of existence) is a process where a unique digital fingerprint (cryptographic hash) of a file is generated and permanently recorded onto a public, decentralized ledger—specifically the Bitcoin blockchain. This record acts as tamper-proof, immutable evidence that the document existed in that exact state at the date and time of the block's creation. No third-party trust is needed, as the math and consensus of the network guarantee its validity.

OpenTimestamps is an open-source, standardized protocol designed for scalable, cost-efficient blockchain timestamping. It works by combining multiple file hashes into a Merkle tree (a cryptographic structure) and recording only the single root hash of this tree on the Bitcoin blockchain. This process, known as batching, allows millions of documents to be timestamped with a single Bitcoin transaction, eliminating transaction fees for users. Yes, batch notarization via OpenTimestamps on Verifybit is completely free.

Yes, in many jurisdictions including the European Union (under the eIDAS regulation) and the United States (via the ESIGN Act and state laws), electronic records and cryptographic proofs are recognized in court. Under eIDAS Art. 25, an electronic time stamp shall not be denied legal effect and admissibility as evidence in legal proceedings solely on the grounds that it is in an electronic form. While it may not automatically carry the presumption of accuracy of a Qualified Time Stamp (QTS) unless combined with specific local regulations, it provides mathematical, indisputable, and mathematically peer-verifiable evidence of a document's integrity and existence at a specific point in time, which is highly persuasive in litigation.

Traditional timestamps rely on centralized Certificate Authorities (CAs) or Time Stamping Authorities (TSAs). If the authority goes out of business, updates their certificate, or is compromised, the validity of your proof can be called into question. Moreover, traditional authorities charge recurring fees. Bitcoin notarization, on the other hand, is decentralized, valid forever, and independent of any single entity. Once recorded, the proof remains verifiable for decades to come, even if Verifybit or the TSAs cease to exist, as the verification depends only on the public Bitcoin network.

When you notarize a file on Verifybit, you receive a .ots receipt file. This file contains the cryptographic path connecting your document's hash to the specific Bitcoin block transaction. You do not need Verifybit to check this. You can download the .ots file and verify it using the official OpenTimestamps client, command-line tools, or third-party web tools. All you need is the original file and the receipt file to verify its existence directly against the public Bitcoin blockchain.

Verifybit respects a zero-knowledge and privacy-first policy. We do not store or upload your files to our servers or the blockchain. All file hashing (generating the cryptographic SHA-256 footprint) is performed locally in your browser or instantly processed and discarded in memory. Only the cryptographic hash (which is a unique alphanumeric string and cannot be reversed to reconstruct the original document) is used for the timestamp transaction. Your confidential files never leave your possession.