What would an academic degree look like if it was designed today? Or a professional certificate?
These are questions we have been working on over the last year, and we are excited to announce the release of Blockchain Certificates (Blockcerts)  — 
an open standard for digital academic certificates on the Bitcoin blockchain.

Is private information now available on the Bitcoin blockchain?

The short answer is no. What is stored on the blockchain is a 1-way hash. This makes it useful only for verification;
i.e. you can hash a certificate and compare to what is on the blockchain. And given what is on the blockchain,
the original data cannot be feasibly recovered. This makes it easy for a recipient to reveal a certificate only to intended third parties.

Are blockchain certificates tamper-proof?

Yes, the blockchain is an immutable and distributed store of transactions, with each block building upon the last.
When a certificate is issued, its data is compressed into a hash and logged on the blockchain.
This generates a “receipt” that can always be checked at a later date.
The verification service validates the signature of the issuer and the certificate data;
it also ensures that the certificate status has not expired or been revoked.