RC4 Stream Cipher (Rivest Cipher 4 or Ron's Code)

(R-C-four)

RC4 is a stream cipher designed by Ron Rivest for then RSA Data Security (now RSA Security). The cipher uses byte-oriented operations with a variable key-size. In general, 8 to 16 machine operations are needed for each byte output. While generally considered secure, it was discovered in 2001 that the initial bytes output were non-random and with a large collection of encrypted text the key could be deduced. As a result, most implementations discard the first 256 (or more) bytes of the stream to skip over that part of the stream.

More Information

• RC4 FAQ
• Wikipedia RC4 Entry