RC4 General Designers Ron Rivest (RSA Security) First published Leaked in 1994 (designed in 1987) Cipher detail Key sizes 40– 2,048 bits State size 2,064 bits ( 1,684 effective) Rounds 256 Speed 7 cycles per byte on original Pentium In, RC4 (also known as ARC4 or ARCFOUR meaning Alleged RC4, see below) is the most widely used software stream cipher and is used in popular protocols such as (SSL) (to protect Internet traffic) and WEP (to secure wireless networks). 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 cryptosystems such as WEP. Contents • • • • • • • • • • • • • • • • • • • • • History RC4 was designed by Ron Rivest of RSA Security in 1987. While it is officially termed 'Rivest Cipher 4', the RC acronym is alternatively understood to stand for 'Ron's Code' (see also, and RC6). RC4 was initially a, but in September 1994 a description of it was anonymously posted to the Cypherpunks mailing list. It was soon posted on the sci. Program Pelacak No Handphone Sign here. crypt, and from there to many sites on the.