catflap.org Online Dictionary Query

  RC4
       
           A cipher designed by RSA Data Security,
          Inc. which can accept keys of arbitrary length, and is
          essentially a pseudo random number generator with the output
          of the generator being XORed with the data stream to produce
          the encrypted data.  For this reason, it is very important
          that the same RC4 key never be used to encrypt two different
          data streams.  The encryption mechanism used to be a trade
          secret, until someone posted source code for an algorithm
          onto Usenet News, claiming it to be equivalent to RC4.  The
          algorithm is very fast, its security is unknown, but breaking
          it does not seem trivial either.  There is very strong
          evidence that the posted algorithm is indeed equivalent to
          RC4.
       
          The United States government routinely approves RC4 with
          40-bit keys for export.  Keys this small can be easily broken
          by governments, criminals, and amateurs.  The exportable
          version of Netscape's Secure Socket Layer, which uses
          RC4-40, was broken by at least two independent groups.
          Breaking it took about eight days; in many universities or
          companies the same computing power is available to any
          computer science student.
       
          See also Damien Doligez's SSL cracking page
          http://pauillac.inria.fr/~doligez/ssl/)" rel="nofollow">(http://pauillac.inria.fr/~doligez/ssl/), RC4 Source and
          http://www.cs.hut.fi/crypto/rc4)" rel="nofollow">Information (http://www.cs.hut.fi/crypto/rc4), SSLeay
          http://www.cs.hut.fi/crypto/software.html#ssleay)" rel="nofollow">(http://www.cs.hut.fi/crypto/software.html#ssleay), Crypto++
          http://www.cs.hut.fi/crypto/software.html#crypto++)" rel="nofollow">(http://www.cs.hut.fi/crypto/software.html#crypto++), Ssh
          http://www.cs.hut.fi/crypto/software.html#ssh)" rel="nofollow">(http://www.cs.hut.fi/crypto/software.html#ssh), A
          collection of articles
          http://www.cs.hut.fi/crypto/rc4-breaking)" rel="nofollow">(http://www.cs.hut.fi/crypto/rc4-breaking).
       
          (1996-10-28)
       
       

  RC4
       Rivest Cipher / Ron's Code 4 (cryptography)