Recommendation for Random Bit Generator (RBG) Constructions

Published

September 25, 2025

Author(s)

Elaine Barker, John Kelsey, Kerry McKay, Allen Roginsky, Meltem Sonmez Turan

Abstract

The NIST Special Publication (SP) 800-90 series of documents supports the generation of high-quality random bits for cryptographic and non-cryptographic use. SP 800-90A, Recommendation for Random Number Generation Using Deterministic Random Bit Generators, specifies several deterministic random bit generator (DRBG) mechanisms based on cryptographic algorithms. SP 800-90B, Recommendation for the Entropy Sources Used for Random Bit Generation, provides guidelines for the development and validation of entropy sources. This document (SP 800-90C) specifies constructions for the implementation of random bit generators (RBGs) that include DRBG mechanisms as specified in SP 800-90A and that use entropy sources as specified in SP 800-90B. Constructions for four classes of RBGs — namely, RBG1, RBG2, RBG3, and RBGC — are specified in this document.

Citation

Special Publication (NIST SP) - 800-90C

Report Number

800-90C

NIST Pub Series

Special Publication (NIST SP)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.SP.800-90C

Local Download

Keywords

deterministic random bit generator (DRBG), entropy, entropy source, random bit generator (RBG), randomness source, RBG1 construction, RBG2 construction, RBG3 construction, RBGC construction, subordinate DRBG (sub-DRBG).

Citation

Barker, E. , Kelsey, J. , McKay, K. , Roginsky, A. and Sonmez Turan, M. (2025), Recommendation for Random Bit Generator (RBG) Constructions, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.SP.800-90C, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960616 (Accessed October 13, 2025)