[PT] 1-Jul-2004

RC4 is a symmetric stream cipher developed by Ron Rivest of RSA Data
Security Inc. The algorithm was a trade secret of RSA but was reverse
engineered and published to the internet in 1994.

The algorithm is a pseudo-random number generator with the output of
the PRNG being xored with the plaintext stream. Decryption is done
by feeding the ciphertext as input with the same key.

This cipher is included as a package in [tcllib]

e.g: 
======
  set src [open $filename r]
  set dst [open ${filename}.rc4 w]
  rc4::rc4 -key Secret -in $src -out $dst
  close $src
  close $dst
======
or just
======
  set crypt [rc4::rc4 -key Secret "Hello, World!"]
======

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See also [encryption], [DES], [AES], [blowfish]

<<categories>> Cryptography | Security