CompTIA Security Plus Mock Test Q1022

Which of the following types of cryptography should be used when minimal overhead is necessary for a mobile device?

A. Block cipher
B. Elliptical curve cryptography
C. Diffie-Hellman algorithm
D. Stream cipher

Correct Answer: B
Section: Cryptography

Regarding the performance of ECC applications on various mobile devices, ECC is the most suitable PKC (Public-key cryptography) scheme for use in a constrained environment.
Note: Elliptic curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. One of the main benefits in
comparison with non-ECC cryptography (with plain Galois fields as a basis) is the same level of security provided by keys of smaller size. Using smaller key size would be faster.

Incorrect Answers:
A, D: Block cipher and stream cipher are cryptography subtypes.’=
C: Diffie-Hellman would require longer keys which would increase overhead.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 245-246, 253