Which of the following DoD Model layer provides non-repudiation services?

A.
Network layer.

B.
Application layer.

C.
Transport layer.

D.
Data link layer.

Explanation:
Non-repudiation is provided by applications such as PGP (Pretty Good Privacy). It is implemented in software
and therefore run in the application layer.
Non-repudiation means that parties involved in a communication cannot deny having participated. It is a
technique that assures genuine communication that cannot subsequently be refuted.
Implementing security at the application layer simplifies the provision of services such as non-repudiation by
giving complete access to the data the user wants to protect.
Incorrect Answers:A: Non-repudiation is implemented at application layer, not at the network layer.
C: Non-repudiation is implemented at application layer, not at the transport layer.
D: Non-repudiation is implemented at application layer, not at the data-link layer.

Conrad, Eric, Seth Misenar and Joshua Feldman, CISSP Study Guide, 2nd Edition, Syngress, Waltham, 2012,
p. 249