PIV Attestation with the YubiKey 5 FIPS 140-3 Series

New intermediate certificates were created in October 2025, and YubiKey 5 FIPS 140-3 Series keys will make use of these new certificates in addition to the existing intermediate certificates. Therefore, to successfully perform PIV attestation with all YubiKey 5 FIPS 140-3 Series keys, you will need to download the new intermediate certificates (linked below) to use during the attestation flow.

Note that the Yubico CA root certificates have not changed, and the existing intermediate certificates (which are still part of the Yubico Intermediate Certificates file) are still valid. The new intermediate certificates were simply added to the file.

Download links:

• Yubico Intermediate Certificates
• Yubico CA Root Certificates

Additional documentation

For more information on what PIV attestation is, see Yubico’s developer documentation.

For guidance on how to perform PIV attestation with the YubiKey PIV Tool CLI, see the YubiKey PIV Tool User Guide.

For general information on the YubiKey 5 FIPS 140-3 Series, see the YubiKey Technical Manual.