Cryptographically signed credentials, traditional notarization, and blockchain badges all aim to make a credential trustworthy, but they solve different problems. Signed credentials prove a specific document is authentic and unaltered. Notarization witnesses an act. Blockchain badges record that an achievement happened on a public ledger.
Cryptographically signed credentials
The institution signs the credential with a private key. Verification checks that signature, so any change to the file is detected and forgery requires the private key. The proof lives in the document and can be checked offline against the institution’s public key. This is the model AcadCert uses.
- Proves: this exact document was issued by this institution.
- Detects: any alteration, plus revocation and expiry.
- Needs: no central authority to trust at verification time.
Traditional notarization
A notary witnesses a signature or certifies a copy and applies a stamp. It establishes that an act took place in front of an authorized person, but the trust rests on the physical stamp and the notary’s register, which are themselves hard to check at a distance and possible to forge.
- Proves: an act was witnessed by an authorized person.
- Detects: little about later tampering with a copy.
- Needs: trust in the stamp and the notary’s records.
Blockchain badges
A badge or hash is written to a public ledger so its existence and time are recorded immutably. This is useful for public, append-only proof of when something was recorded, but it adds cost and complexity, often still relies on a signature for authenticity, and can expose metadata publicly. The ledger proves a record exists, not that a particular PDF in your inbox is the genuine, unaltered credential.
- Proves: a record existed at a point in time on a public ledger.
- Detects: changes to the ledger entry, not necessarily to a file.
- Needs: the chain, and usually a signature underneath anyway.
Which to choose
For academic credentials, the practical question is usually: can a verifier confirm this diploma is real and unaltered, quickly and for free? Cryptographic signing answers that directly, with an independent timestamp for the time element and instant revocation when a credential must be withdrawn, and without putting personal data on a public ledger.