CompTIA Security+ Question A-22

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

Answer: B

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.