Which of the following services is NOT provided by the digital signature standard (DSS)?

A.
Encryption

B.
Integrity

C.
Digital signature

D.
Authentication

Explanation:
Digital signatures do not provide encryption.
The purpose of digital signatures is to detect unauthorized modifications of data, and to authenticate the identity
of the signatories and non-repudiation. These functions are accomplished by generating a block of data that is
usually smaller than the size of the original data. This smaller block of data is bound to the original data and to
the identity of the sender. This binding verifies the integrity of data and provides non-repudiation. To quote the
National Institute Standards and Technology (NIST) Digital Signature Standard (DSS): Digital signatures are
used to detect unauthorized modifications to data and to authenticate the identity of the signatory. In addition,
the recipient of signed data can use a digital signature in proving to a third party that the signature was in fact
generated by the signatory.
Incorrect Answers:
B: Digital signatures do provide integrity.
C: The digital signature standard (DSS) as its name suggests is all about digital signatures.
D: Digital signatures do provide authentication.

Krutz, Ronald L. and Russel Dean Vines, The CISSP Prep Guide: Mastering the Ten Domains of Computer
Security, John Wiley & Sons, New York, 2001, p. 151