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 Obtaining Assurances for Digital Signature Applications



Elaine B. Barker


Entities participating in the generation or verification of digital signatures depend on the authenticity of the process. This Recommendation specifies methods for obtaining the assurances necessary for valid digital signatures: assurance of domain parameter validity, assurance of public key validity, assurance that the key pair owner actually possesses the private key, and assurance of the identity of the key pair owner.
Special Publication (NIST SP) - 800-89
Report Number


Assurance, Certification Authority, digital signatures, timestamp token, Trusted Timestamp Authority


Barker, E. (2006), Recommendation for Obtaining Assurances for Digital Signature Applications, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 14, 2024)


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

Created November 30, 2006, Updated January 27, 2020