Random Bit Generation RBG

The National Institute of Standards and Technology (NIST) Random Bit Generation (RBG) project focuses on the development and validation of generating random numbers that are essential for cryptographic and security applications.

SP 800-90 Series

The project provides guidelines through the SP 800-90 series, which includes recommendations on deterministic random bit generator (DRBG) mechanisms, entropy sources, and construction principles for RBGs, and has three parts:

• SP 800-90A, Recommendation for Random Number Generation Using Deterministic Random Bit Generators, specifies mechanisms for generating random bits using deterministic methods. NIST is revising SP 800 90A to be consistent with SP 800-90C.
• SP 800-90B, Recommendation for the Entropy Sources Used for Random Bit Generation, specifies the design principles and requirements for the entropy sources used by RBGs and the tests for the validation of entropy sources.
• SP 800-90C, Recommendation for Random Bit Generator (RBG) Constructions, specifies constructions for the implementation of RBGs. 

The following figure explains the relationship of the three parts of the series.

NIST IR 8427, Discussion on the Full Entropy Assumption of the SP 800 90 Series, provides technical discussions to support the full entropy definition used in the SP 800 90 series.  

Validation of Random Bit Generators

The SP 800 90 series provides a basis for validation by NIST's Cryptographic Algorithm Validation Program (CAVP) and Cryptographic Module Validation Program (CMVP).

• Implementation Guidance (See Sections 14.5, 7.14, 7.15, 7.18, 7.19 and 7.20)
• Examples with Intermediate Values
• Object Identifiers (OIDs)
• Entropy Source Validations

SP 800-22

SP 800-22, A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications, specifies a set of statistical tests for randomness.  

In 2022, NIST Crypto Publication Review Board completed a review of SP 800-22 and is planning to revise the publication.

NIST Randomness Beacon

NIST also hosts the NIST Randomness Beacon as a source of public randomness. The service includes multiple independent, commercially available sources of randomness.

External Links

• BSI Random Number Generation website
• The Cryptographic Module User Forum
• ISO/IEC 18031:2011(en) Information technology — Security techniques — Random bit generation
• ISO/IEC 20543:2019(en) Information technology — Security techniques — Test and analysis methods for random bit generators within ISO/IEC 19790 and ISO/IEC 15408