INTRO (9) NetBSD Kernel Developer's Manual INTRO (9) NAME ...

ARC4RANDOM (9) NetBSD Kernel Developer’s Manual ARC4RANDOM (9)NAMEarc4random —arc4 random number generatorSYNOPSIS#include #include uint32_tarc4random(void);DESCRIPTIONThe arc4random() function provides a high quality 32-bit pseudo-random number very quickly.arc4random() seeds itself on a regular basis from the kernel strong random number subsystem describedin rnd(4). On each call, an ARC4 generator is used to generate a new result. The arc4random() functionuses the ARC4 cipher key stream generator, which uses 8∗8 8bit S-Boxes. The S-Boxes can be in about(2∗∗1700) states.arc4random() fits into a middle ground not covered by other subsystems such as the strong, slow, andresource expensive random devices described in rnd(4) versus the fast but poor quality interfaces such asrandom().SEE ALSOarc4random(3), rnd(4)HISTORYAn algorithm called RC4 was designed by RSA Data Security, Inc. It was considered a trade secret, but nottrademarked. Because it was a trade secret, it obviously could not be patented. Aclone of this was postedanonymously to USENET and confirmed to be equivalent by several sources who had access to the originalcipher. Because of the trade secret situation, RSA Data Security, Inc. can do nothing about the release of theARC4 algorithm. Since RC4 used to be a trade secret, the cipher is now referred to as ARC4.These functions first appeared in OpenBSD 2.1.NetBSD 3.0 April 15, 1997 1