Upload a .primestamp proof bundle file to verify offline proofs.
PrimeStamp is a decentralized document authentication system that combines blockchain timestamping with Prime-Space fingerprinting. It provides cryptographic proof of document existence, authorship, and integrity without revealing the document contents to anyone.
Stamps are anchored to multiple blockchains (Bitcoin, Ethereum, Polygon and more) so anyone can independently verify them at any time.
Hash your document and sign it with your cryptographic identity.
Submit the hash to Bitcoin, Ethereum, and other blockchains for immutable timestamping.
Anyone can check the blockchain proof here — no app, no login, no cost.