Domain: Verifiable Certificates
- Education [Reputation, Certification Management]
- Integrity Verification [Intellectual property, Insurance, Counterfeit]
Problem identification:
Academic certificates are historically issued by institutions in the paper/digital form and a corresponding internal record is kept whenever a certificate is issued. Even with massive growth of Information Technology, this scenario has been rudimentary; and we have seen myriads of fraudulent cases about forging academic certificates for jobs etc.
To ensure that the academic certificate that the candidate furnishes is authentic, an employer has to go through a lot of toil stretching over weeks, tens of emails and broken pieces of information. The outcome being some employers conveniently skipping this process of verification. Who would want to be treated by a doctor who got the job by using a fake certificate? Or to be taught by a professor who got in using a fraudulent certificate?
So, the question is how to make this verification process authentic but also keep it simple, fast and efficient.
Why Blockchain:
[traceability, transparency, security, control]
Blockchain has certain features that make it ideal for establishing trust in any document anchored to it.
- Transparent: All data embedded in the document is available for anyone with access to the public key to review.
- Immutable: Data relating to a document can only be added on the structure; cannot be altered or removed.
- Open: The network is open for anyone to participate.
- Secure: Powered by strong cryptography.
Via the use of blockchain’s characteristics the fraudulent certificates through easy authentication processes can be dealt with.
Functional Description
- Issuance of Certificates
- Metadata relating to the certificate is attached to a PDF file (optional)
- A fingerprint of the whole document (PDF incl. the metadata) is included
in a Bitcoin transaction - The transaction details are added back to the metadata on the PDF file
- The certificates are disseminated to owners
2. Validation of Certificates
- Go to an online validator found on issuer’s and other websites
- Upload the PDF file
- Get an immediate response as to its validity
3. Revocation of Certificates
a. An additional transaction is created on the Blockchain that invalidates previous records without erasing audit trail
Technology used
- Blockchain: Bitcoin
- Software:
- Main characteristics of the chosen blockchain: Public blockchain
- Consensus mechanism: Proof-of-Work
The ledger contains a record of all bitcoin transactions, arranged in sequential “blocks,” so that no user is allowed to spend any of their holdings twice. In order to prevent tampering, the ledger is public, or “distributed”; an altered version would quickly be rejected by other users.
Tampering is detected in practice through the hashes that serve as proof of work. Bitcoin uses SHA-256 hash function – an one way function (meaning that it cannot be used to obtain the original data, only to check that the data that generated the hash matches the original data).
Current status
- The project is currently running as a commercial application.
- URL: https://block.co/
- Source code:Source code and instructions on setting up the validator application can be found on: https://github.com/UniversityOfNicosia/blockchain-certificates-validation
Focus point commentary indicating the value of the case study in relation with learning modules
Learning Modules Focus Points
Encryption techniques Elliptic Curve Digital Signature Algorithm (ECDSA)
Consensus Proof-of-Work
Limitations:
- No reported limitations.
Alternatives Approaches:
- Blockcerts (https://www.blockcerts.org)
References
- Konstantinos Karasavvas, Revoking Records in an immutable ledger: A platform for issuing and revoking official documents on public blockchains, CVCBT 2018: 105-111