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.
Famous quotes containing the word yarrow:
““O haud your tongue, my father dear,
An’ dinna grieve your Sarah;
A better lord was never born
Than him I lost on Yarrow.”
—Unknown. The Dowie Houms o’ Yarrow (l. 53–56)