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

Explanation:
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, Sixth Edition, Sybex, Indianapolis, 2014, pp 245-246, 253
http://www.studymode.com/essays/Elliptic-Curve-Cryptography-And-Its-Applications- 1560318.html
http://en.wikipedia.org/wiki/Elliptic_curve_cryptography