Which of the following is a stream cipher A DES B Skipjack C

Which of the following is a stream cipher?

A. DES

B. Skipjack

C. RC4

D. Twofish

Solution

C. RC4 is a stream cipher. It has been implemented in products such as SSL and WEP. Answer A is incorrect because DES is a block cipher with a 56-bit key size. Answer B is incorrect because Skipjack is a block cipher with a default 80-bit key size. Answer D is incorrect because Twofish is a 256-bit key size block cipher