Question 48

Explanation

A digital signature is the result of a cryptographic transformation of data that is useful for providing: authentication of data origin, data integrity, and non-repudiation of the signer. However, digital signatures cannot guarantee confidentiality (i.e., the property that data or information will not be made available or disclosed).

For example, when a document is digitally signed, anyone with the public key can verify the signature, but the content of the document is not encrypted by the digital signature itself. If confidentiality is required, the document must be separately encrypted.

Integrity is incorrect because digital signatures ensure the integrity of a message by allowing the recipient to detect any changes to the content of the message after it has been signed. Non-repudiation, also incorrect, because digital signatures prevent the sender from denying the authenticity of the signed message. Authentication, incorrect because digital signatures authenticate the identity of the sender by linking them to the document or message they signed.