Verify Proof of Existence

WHAT IT DOES

Verify Proof of Existence enables you to verify that a document's proof of existence is valid on the blockchain. Proof of existence is the foundational use case for blockchain timestamping—proving that a document existed at a specific point in time. This tool takes a document (file or hash) and a transaction hash, recomputes the document hash, and verifies that it matches the hash stored on the blockchain. It also retrieves the block timestamp to confirm when the proof was created. This is essential for intellectual property protection, legal evidence, audit trails, and any application requiring verification of document integrity and timestamp. The tool provides clear output showing the document hash, transaction hash, block timestamp, and verification status.

HOW TO USE

Connect your wallet using the BGWallet connector (required for context). Select the verification method: "File upload" to upload the original document, or "Document hash" to enter the hash directly. If using file upload, click the file input to select the document. Enter the transaction hash that was generated when the proof was created. Click "Verify Proof" to perform the verification. The tool computes the document hash and verifies it against the transaction data. The tool displays the document hash, transaction hash, block timestamp, and verification status. You can copy the hash or view the transaction on the blockchain explorer. The result includes a detailed breakdown showing the verification details and status.

TECHNICAL MECHANISM

This tool implements proof of existence verification by comparing document hashes with on-chain data. The verification process: (1) the document is hashed using Keccak-256 (or the provided hash is used); (2) the transaction is retrieved from the blockchain using the transaction hash; (3) the stored hash is extracted from the transaction data; (4) the hashes are compared; (5) the block timestamp is retrieved to confirm the time of proof creation. The Keccak-256 hash is a one-way function that uniquely identifies the document content—any change to the document will produce a different hash. The blockchain provides a permanent, tamper-proof record of when the proof was created. All computation is performed locally in the browser with data fetched from the blockchain for verification.

WHAT IT CANNOT SEE

This tool cannot verify that the document content matches the hash without the original file; the file must be provided. It does not support verification of proofs created on private or permissioned blockchains; only public EVM chains are supported. The tool cannot verify the document's authenticity beyond the hash; it only confirms the hash matches. It does not support verification of proofs from non-EVM chains. The tool cannot guarantee that the proof will be accepted as legal proof in all jurisdictions—legal recognition varies. It does not support batch verification of multiple documents; each document must be verified separately. The tool cannot verify the document's integrity without the original file or hash. It does not support proof verification without a transaction hash or block number.

PLEASE NOTE

This tool is designed for developers and users needing to verify blockchain proof of existence. The document hash uniquely identifies the document content. The blockchain timestamp provides a permanent, verifiable record. The tool fetches transaction data from the blockchain to verify the proof. For production use, ensure you have the correct transaction hash. Always verify the proof by recomputing the hash from the original document. The tool is intended for testing, development, and educational purposes.