Create Proof of Existence

WHAT IT DOES

Create Proof of Existence enables you to create an immutable, verifiable proof that a document existed at a specific point in time. This is the foundational use case for blockchain timestamping—proving that you had a document at a certain time without revealing its contents. The tool takes a document (file or hash), computes its Keccak-256 hash, and stores it on the blockchain via a transaction. The resulting transaction serves as a permanent, tamper-proof record that the document existed at the time of the transaction. This is essential for intellectual property protection, legal evidence, audit trails, and any application requiring proof of document integrity and timestamp. The tool provides clear output showing the document name, size, hash, and transaction hash.

HOW TO USE

Connect your wallet using the BGWallet connector (required for context). Select the input 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 a document name and optional description. Click "Create Proof of Existence" to process the document. The tool computes the document hash (or uses the provided hash) and simulates a transaction to store it on the blockchain. The tool displays the document name, size, hash, and transaction hash. You can copy the hash or view the transaction on the blockchain explorer. The result includes a detailed breakdown showing the proof creation details and status.

TECHNICAL MECHANISM

This tool implements proof of existence by storing a document hash on the blockchain. The proof creation process: (1) the document is read as an ArrayBuffer (or the provided hash is used); (2) the Keccak-256 hash of the document bytes is computed; (3) a transaction is sent to store the hash on the blockchain; (4) the transaction hash serves as the proof of existence. 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 hash was stored. All computation is performed locally in the browser with no data sent to external servers except for the transaction itself.

WHAT IT CANNOT SEE

This tool cannot guarantee that the proof of existence will be accepted as legal proof in all jurisdictions—legal recognition varies by jurisdiction. It does not verify the document's content or authenticity beyond the hash; it only proves the document existed at the time of timestamping. The tool cannot recover the original document from the hash; the hash is one-way. It does not support proof creation without sufficient gas fees; transactions require gas. The tool cannot guarantee the transaction will be mined within a specific timeframe. It does not support batch proof creation of multiple documents in a single transaction. The tool cannot verify the document's integrity without the original file. It does not support private or permissioned blockchains.

PLEASE NOTE

This tool is designed for developers and users needing immutable proof of document existence. The Keccak-256 hash uniquely identifies the document content. The blockchain timestamp provides a permanent, verifiable record. For production use, ensure you have sufficient gas fees for the transaction. Always verify the proof by recomputing the hash from the original document. The tool is intended for testing, development, and educational purposes.