arc4random(3)

  The arc4random(3) interface, available in the OpenBSD libc, makes use of the kernel randomness pool, described in the previous section, for seeding the keystream generator employed by the ARC4 cipher (a cipher equivalent to RSADSI's RC4). The interface provides support for applications to ``add'' randomness to the pool maintained by arc4random(3). This interface is intended as a drop-in replacement for the traditional Unix random(3) interface, for those applications that need higher-quality random numbers.