Q.Choose the correct option: A digital signature under the IT Act, 2000 is created using —

A digital signature is a technical mechanism, not a picture of a signature; recognising the technology behind it separates it from a mere digitised image.

Section 3 of the Act authenticates an electronic record by a digital signature based on a public/private key pair and a hash — giving both authentication and integrity.

The question tests whether you can distinguish a genuine digital signature from things that only look like signatures.

• (a) a scanned image of a handwritten signature — this is a digitised signature; it proves nothing about integrity and can be copied, so it is not a digital signature.
• (b) asymmetric cryptography and a hash function — correct. Under Section 3, a digital signature is created with a private-key/public-key pair and a hash of the record, which proves who signed (authentication) and that the record was not altered (integrity).
• (c) a simple password — a password authenticates a login but does not sign a record or guarantee its integrity.
• (d) a photograph of the signer — irrelevant to signing an electronic record.

Do not confuse a digital signature (cryptographic) with a digitised signature (a scanned image). Only the former provides authentication and integrity.