Yarrow algorithm
From Wikipedia, the free encyclopedia
The Yarrow algorithm is a cryptographically secure pseudorandom number generator. The name is taken from the yarrow plant, the stalks of which are dried and used as a randomising agent in I Ching divination.
It was designed by Bruce Schneier, John Kelsey, and Niels Ferguson of Counterpane Labs (Kelsey et. al, 1999). The Yarrow algorithm is explicitly unpatented and royalty-free; no license is required to use it. Yarrow is incorporated in Mac OS X and FreeBSD for their /dev/random devices.
An improved design from Ferguson and Schneier, Fortuna, is described in their book, Practical Cryptography.