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.

NIST SP 800-90C (2nd Public Draft)

Recommendation for Random Bit Generator (RBG) Constructions

Date Published: April 2016
Comments Due: June 13, 2016 (public comment period is CLOSED)
Email Questions to:


Elaine Barker (NIST), John Kelsey (NIST)


NIST invites comments on the second draft of Special Publication (SP) 800-90C, Recommendation for Random Bit Generator (RBG) Constructions. This Recommendation specifies constructions for the implementation of RBGs. An RBG may be a deterministic random bit generator (DRBG) or a non-deterministic random bit generator (NRBG). The constructed RBGs consist of DRBG mechanisms, as specified in SP 800-90A, and entropy sources, as specified in SP 800-90B.

On May 2-3, 2016, NIST hosted a workshop on Random Number Generation to discuss the SP 800-90 series of documents--specifically, SP 800-90B and SP 800-90C.



non-deterministic random bit generator (NRBG); random number generator; randomness source  ; ; deterministic random bit generator (DRBG); construction; entropy source; entropy
Control Families

System and Communications Protection


Second Draft SP 800-90C (pdf)

Supplemental Material:
Comment Template (docx)

Document History:
09/05/12: SP 800-90C (Draft)
04/13/16: SP 800-90C (Draft)
09/07/22: SP 800-90C (Draft)


Security and Privacy

random number generation