> (and to some extent NIST, because Ed25519 has not been approved by them).
Ed25519 (and Ed448) have been approved for use in FIPS 186-5 as of February 2023:
* https://en.wikipedia.org/wiki/EdDSA#Standardization_and_impl...
Ed25519 (and Ed448) have been approved for use in FIPS 186-5 as of February 2023:
* https://en.wikipedia.org/wiki/EdDSA#Standardization_and_impl...
So on the general web it seems remote at best.
NIST P-curve certs were acceptable per the Base Requirements all the way back in 2012
* https://cabforum.org/uploads/Baseline_Requirements_V1_1.pdf
See "Appendix A - Cryptographic Algorithm and Key Requirements (Normative)", (3) Subscriber Certificates.
Ed25519 certs do work with TLS (OpenSSL support at least), but without browser adoption it's machine to machine with private CA only .