Using blockchain technology to notarize important documents

Most people have by now heard about "the blockchain", but there are in fact hundreds of various blockchains running in parallel. Bitcoin has its own blockchain, and that is probably what people mean when they say "THE Blockchain". There are numerous AltCoins like LiteCoin, NameCoin, DASH and ETH running chains of their own.

So how does this relate to a "Notary app" - and what does that mean?

A "public notary" or "Notarius Publicus is traditionally some sort of official person, sitting in an office, looking at your document and then giving you their stamp or signature that they have seen and verified that the document exists and looks valid.

The BITNATION Public Notary is a digital version of this person.
You bring your PDF document, generate a keypair with a simple press of a button - and present it to the Notary through the "SEND" button.

This generates a Notary Certificate, that you need to copy and save, with your original file.

What happens is:

- the document is hashed (mathematical checksum process)
- digitally signed with a ECDSA keypair (very secure and legit algorithm for digital signatures)
- the hash, public key and digital signature of the document is inserted into a blockchain with a transaction

This procedure gives us:

- data integrity (the hash is always the same for the same document)

- offline verification of data integrity (using the hash, the public key and the signature)

- a timestamp and "Proof-of-Existence" in a distributed blockchain (Horizon "HZ")

Since the hash and all things needed for verification is included in the blockchain insert, we only need to keep safe the Horizon transaction number (HZ TX returned in the certificate) to be able to find the verification data and time of notarization.

Anyone can repeat the same process, using the BITNATION Public Notary, to verify the document has not been altered from the time of notarization. This is due to the hash always being the same.

Here is a video showing how to use the app: https://vimeo.com/179633547