Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Recommendation for the Entropy Sources Used for Random Bit Generation



Meltem Sonmez Turan, Elaine B. Barker, John M. Kelsey, Kerry A. McKay, Mary L. Baish, Mike Boyle


This Recommendation specifies the design principles and requirements for the entropy sources used by Random Bit Generators, and the tests for the validation of entropy sources. These entropy sources are intended to be combined with Deterministic Random Bit Generator mechanisms that are specified in SP 800-90A to construct Random Bit Generators, as specified in SP 800-90C.
Special Publication (NIST SP) - 800-90B
Report Number


Conditioning functions, entropy source, health testing, min-entropy, noise source, predictors, random number generators


Sonmez, M. , Barker, E. , Kelsey, J. , McKay, K. , Baish, M. and Boyle, M. (2018), Recommendation for the Entropy Sources Used for Random Bit Generation, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 30, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created January 10, 2018, Updated November 10, 2018