What is "Notarization"?

By means of "notarization" it can be proven that an electronic document existed in a certain form at a certain time and has not been changed since then. Another term for this process is "Proof of Existence".

When creating a notarization, a unique fingerprint of a document (the so-called hash value) is calculated and stored in a blockchain, together with a timestamp. The blockchain guarantees the immutability of this data.

If, at a later date, the existence of the document at the specified time and the integrity of the document shall be proven, the data is retrieved from the blockchain and compared with the available information.

Creation of the proof

To create a notarization, choose a document. The file is not uploaded to the server, but the hash value is calculated locally in the browser.

After storing the information in the blockchain, the results (timestamp, hash value, transaction ID ...) are displayed and can be downloaded in the form of a ceritificate (as PDF file).

Verification of the proof

To verify existence and integrity of the document later, either the transaction ID of the creation or the hash value of the document must be available. The hash value of the document can also be recalculated. Based on this input, the corresponding data is searched in the blockchain. The result will show the data of the transaction (timestamp, hash value and transaction ID) and the data of the block where the transaction was stored (blockhash, blocktime and confirmations).

If the same document has been notarized several times, there are also several entries. The oldest entry is the most relevant.

Status of this system

This system is in production mode, running on the "DatNoS"-Blockchain. For further information visit Blockchain Initiative Austria.