Woleet add-in for Outlook allows to:
- Timestamp an email or an attachment to prove its existence at a given date
- Verify the timestamps of an email or an attachment (whoever timestamped it)
- Sign an email or an attachment using a highly secured Ledger Nano S hardware Bitcoin wallet
- Verify when and who signed an email or an attachment (number of signatures is not limited)
A proof of existence is a self contained cryptographic proof (available as a JSON file compliant with the Chainpoint format linking the digital fingerprint of the data to a Bitcoin transaction. This link allows to prove that the data existed at the time of the transaction.
A proof of signature is similar: it is proposed by Woleet as an improvement of the Chainpoint format. It links the digital fingerprint of the signature of the data to a Bitcoin transaction. This link allows to prove that the signature (and so the signed data) existed at the time of the transaction. Signatures are created using the Bitcoin signature scheme, and so signing can be performed using a regular Bitcoin hardware wallet like the Ledger Nano S.
Generated proofs can be verified with no intermediary, not even Woleet (since the Bitcoin blockchain is a public ledger). Various open source tools exist (like http://btcproof.info) and the Woleet ProofDesk web application can also be used.
Creating a proof of existence or signature for an email or attachment doesn’t modify nor leak the content to the email or attachment: the digital fingerprint is computed client side by the browser, and the original content cannot be recovered from it (digital fingerprinting is a one way function).