Fortuna is a family of cryptographically secure PRNGs; devised by Bruce Schneier and Niels Ferguson, who published it in 2003.

Fortuna is a family of cryptographically secure PRNGs; devised by Bruce Schneier and Niels Ferguson, who published it in 2003.

As stated on the web-page of Bruce Schneier, Fortuna was made to replace the earlier Yarrow PRNG. The Fortuna paper, which describes the algorithm, is available as PDF via the website of Mr. Schneier.