Disable Certificate Transparency enforcement for a list of legacy certificate authorities

Disables enforcing Certificate Transparency requirements for a list of legacy certificate authorities (Cas).

This policy lets you disable Certificate Transparency disclosure requirements for certificate chains that contain certificates with one of the specified subjectPublicKeyInfo hashes. This allows certificates that would otherwise be untrusted because they were not properly publicly disclosed, continue to be used for enterprise hosts.

In order for Certificate Transparency enforcement to be disabled, you must set the hash to a subjectPublicKeyInfo appearing in a CA certificate that is recognized as a legacy certificate authority (CA). A legacy CA is a CA that has been publicly trusted by default by one or more operating systems supported by Microsoft Edge.

You specify a subjectPublicKeyInfo hash by concatenating the hash algorithm name, the "/" character, and the Base64 encoding of that hash algorithm applied to the DER-encoded subjectPublicKeyInfo of the specified certificate. This Base64 encoding is the same format as an SPKI Fingerprint, as defined in RFC 7469, Section 2.4. Unrecognized hash algorithms are ignored. The only supported hash algorithm at this time is "sha256".

If you don't configure this policy, any certificate that's required to be disclosed via Certificate Transparency will be treated as untrusted if it isn't disclosed according to the Certificate Transparency policy.

Example value:


Supported on: Microsoft Edge version 77, Windows 7 or later

Disable Certificate Transparency enforcement for a list of legacy certificate authorities

Registry PathSoftware\Policies\Microsoft\Edge\CertificateTransparencyEnforcementDisabledForLegacyCas
Value Name{number}
Value TypeREG_SZ
Default Value


Administrative Templates (Computers)

Administrative Templates (Users)