Blockchain and electronic notarization

Blockchain notarization consists of anchoring the cryptographic fingerprint (SHA-256 hash) of a document in an immutable distributed ledger (Bitcoin, Ethereum, etc.) to prove its existence at a given point in time. Unlike RFC 3161 qualified timestamps, blockchain notarization is not recognized as legal proof under eIDAS: it constitutes admissible evidence before certain jurisdictions but does not replace an accredited QTSP. Its advantage is decentralization: the proof survives the disappearance of the service provider. In an enterprise context, blockchain is most relevant for archiving supplementary evidence (hash published on-chain) as a redundancy layer above standard electronic archiving with evidentiary value.