Tamper test

A notary attests that a stamped paper exists. A cryptographic signature attests that an issuer — say, UIDAI — emitted exactly this data. The two look the same when nothing has changed. Tamper with one field and the difference becomes the whole point.

Figure

Flip the toggle to alter one field of the credential — then watch which attestation catches it and which doesn't.

Aadhaar verifiable credential
Name
Rahul Matthan
DOB
1972-08-14
Aadhaar
XXXX XXXX 3927
Verification
Notary's stamp
Attests that the document existed at the time of stamping. The notary cannot revisit it.
Stamped
UIDAI digital signature
Verifies that the exact contents of this credential were signed by UIDAI.
Verified

Part of Do We Need Notaries in Ex Machina. Other explorables.