ARC4RANDOM(3)             OpenBSD Programmer's Manual            ARC4RANDOM(3)

NAME
     arc4random, arc4random_stir, arc4random_addrandom - arc4 random number
     generator



SYNOPSIS
     #include <stdlib.h>

     u_int32_t
     arc4random(void);

     void
     arc4random_stir(void);

     void
     arc4random_addrandom(u_char *dat, int datlen);

DESCRIPTION
     The arc4random() function uses the key stream generator employed by the
     arc4 cipher, which uses 8*8 8 bit S-Boxes. The S-Boxes can be in about
     (2**1700) states.

     The arc4random_stir() function reads data from /dev/arandom and uses it
     to permute the S-Boxes via arc4random_addrandom().

     There is no need to call arc4random_stir() before using arc4random(),
     since arc4random() automatically initializes itself.

SEE ALSO
     rand(3),  rand48(3),  random(3)

HISTORY
     An algorithm call RC4 was designed by RSA Data Security, Inc.  It was
     considered a trade secret, but not trademarked.  A clone of this was
     posted anonymously to the USENET and was confirmed to be equivalent by
     several sources who had access to the original cipher.  Because of the
     trade secret situation, RSA Data Security, Inc. can do nothing about the
     situation.  Since RC4 used to be a trade secret, the cipher is now re-
     ferred to as ARC4.

OpenBSD 2.6                     April 15, 1997                               1