Document certification with a time stamp on Kaspa

Proovik certifies the existence of digital content (files, documents, images, etc.) at a specific point in time. We do NOT verify the content, authorship, or legality of the document. We only prove that a specific file existed at a given moment.

No. Your file never leaves your device. We calculate the SHA-256 hash locally in your browser and only that hash (a 64-character string) is sent to be recorded on the blockchain. It is mathematically impossible to reconstruct the original file from the hash.

Proovik issues a NON-qualified electronic time stamp within the meaning of Art. 3(16)(i) of Regulation (EU) 910/2014 (eIDAS). Under Art. 41(1), it shall not be denied legal effect and admissibility as evidence in legal proceedings solely on the grounds that it is in electronic form or that it is not qualified. What it does NOT carry is the presumption of accuracy of the date and time under Art. 41(2), which is reserved for qualified time stamps issued by providers on the trusted lists. Proovik does not replace a notary or a qualified trust service provider, and weighing the evidence is always for the court. Outside the EU, treatment depends on the jurisdiction: consult a lawyer for your case.

Kaspa is a public proof-of-work network with a BlockDAG structure: instead of a single chain of blocks in a row, it accepts several blocks at once. It produces on the order of ten blocks per second, so a seal is usually confirmed in seconds rather than minutes or hours. For proof of existence and prior date that matters: the sooner the hash enters a time-stamped block, the tighter the date you can prove. The cost per transaction is a fraction of a cent, and the proof is verified with the same mathematics as any other proof-of-work chain.

Any type of digital file: PDF, DOCX, images (JPG, PNG), videos (MP4), code, ZIP files, etc. There is no file type restriction since we only process the hash.