In May 2021, NIST's Crypto Publication Review Board initiated a review process for the following publications:

• NIST Special Publication (SP) 800-15 (1998), Minimum Interoperability Specification for PKI Components (MISPC), Version 1 
• NIST SP 800-25 (2000) Federal Agency Use of Public Key Technology for Digital Signatures and Authentication
• NIST SP 800-32 (2001) Introduction to Public Key Technology and the Federal PKI Infrastructure

On August 4, 2021, NIST proposed to withdraw those publications and called for comments on that decision proposal. During that comment period, which ended September 3, 2021, NIST received no public comments on SP 800-25 or SP 800-32 and one set of comments on SP 800-15.

NIST is withdrawing all three publications, effective immediately. NIST’s rationale for withdrawing each publication is included in the August 4th announcement, which also stated that:

rather than developing up-to-date revisions or replacements for the three publications, NIST instead recommends https://idmanagement.gov as an alternative source of information, in particular, https://www.idmanagement.gov/manage/, https://fpki.idmanagement.gov/, and https://www.idmanagement.gov/topics/fpki/.

Information about the review process is available at NIST's Crypto Publication Review Project.