Which of the following ciphers would be BEST used to encrypt streaming video?

A.
RSA

B.
RC4

C.
SHA1

D.
3DES

Explanation:
In cryptography, RC4 is the most widely used software stream cipher and is used in popular
Internet protocols such as Transport Layer Security (TLS). While remarkable for its simplicity and
speed in software, RC4 has weaknesses that argue against its use in new systems. It is especially
vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or
related keys are used; some ways of using RC4 can lead to very insecure protocols such as WEP.
Because RC4 is a stream cipher, it is more malleable than common block ciphers. If not used
together with a strong message authentication code (MAC), then encryption is vulnerable to a bitflipping attack. The cipher is also vulnerable to a stream cipher attack if not implemented correctly.

Furthermore, inadvertent double encryption of a message with the same key may accidentally
output plaintext rather than ciphertext because the involutory nature of the XOR function would
result in the second operation reversing the first.
It is noteworthy, however, that RC4, being a stream cipher, was for a period of time the only
common cipher that was immune to the 2011 BEAST attack on TLS 1.0. The attack exploits a
known weakness in the way cipher block chaining mode is used with all of the other ciphers
supported by TLS 1.0, which are all block ciphers.