Cryptographic digest (or hash amount) has been calculated from this file using SHA256 algorithm and then saved in the blockchain. The original link to this file is also now permanently saved.
What does it mean
It means that this confirmed blockchain transaction contains a file (a document), hash amount of which has been permanently stored inside transaction. It is now impossible to modify or backdate this file based on blockchain principle (link). If at later date you want to verify this document, and you have a copy of it, you can upload it using form above, calculate its hash amount and compare with the hash amount stored in the blockchain. Matching hash amounts is a 100% probability that the document is authentic.
Hash function algorithm of SHA256 has been developed by NSA. More info http://en.wikipedia.org/wiki/SHA-2
How to make sure that file matches the signature
You need to calculate SHA256 hash amount and compare it with the one saved in the blockchain.
How to calculate SHA256 hash amount
Upload file (or paste in case of text data) into the form on this page. Hash will be calculated inside the browser and never send over internet. Calculated result will be compared with the file previously saved and result will be shown to you.
If you don't trust our page, feel free to calculate hash amount of your file using independent tools. Just google “calculate sha256 hash”.
You can also calculate hash by yourself, using open source code.