Could a C25519/ED25519 cryptographic module be FIPS certified?
Could a C25519/ED25519 cryptographic module be FIPS certified?


Likely yes in the near future—although ‘near’ is measured relative to the pace of a US federal government bureaucracy.

On 2019-10-31, NIST submitted a request for comments to the Federal Register on drafts for FIPS 186-5 and NIST SP 800-186 that include the Montgomery and Edwards curve shapes; the particular curves Curve25519, Curve448, edwards25519, and edwards448; and the EdDSA signature scheme instantiated with them, as defined in RFC 7748 and RFC 8032.  Comments are due by 2020-01-20.

(The updates do not cover the X25519/X448 DH functions, but NIST's late 2017 announcement of the upcoming changes also mentioned future updates to NIST SP 800-56A, which covers key agreement.)