Consider the following statements:A digital signature is1.an electronic record that identifies the certifying authority issuing it2.used to serve as a proof of identity of an individual to access information or serve on Internet3.an electronic method of signing an electronic document and ensuring that the original content is unchangedWhich of the statements given above is/are correct?

1. A

   1 only

   (a) 1 only. Statement 1 describes a digital signature certificate / the certifying authority’s electronic record more than the signature itself. It is not the keyed meaning. Not the key.

2. B

   2 and 3 only

   (b) 2 and 3 only. Statement 2 is the function of a digital certificate as identity proof to access services, not the definition of a digital signature. Not the key.

3. C

   3 only

   (c) 3 only. A digital signature is an electronic method of signing an electronic document and of ensuring that the original content is unchanged (integrity and authenticity via public-key cryptography). That is the official key.

4. D

   1, 2 and 3

   (d) 1, 2 and 3. Statements 1 and 2 mix in certificate/identity functions. Not the key.

Summary. Official key is (c). A digital signature signs and seals content. Identifying the certifying authority and proving identity to access a website are jobs of the digital signature certificate and the PKI, not the signature definition in statement 3. Honour (c).