DigiCert: P-384,ecdsa-with-SHA512 Certificates

DigiCert reported a compliance issue regarding certificates signed with a P-384 sub-CA key using the ecdsa-with-SHA512 signature algorithm, which violated Mozilla's policy. The issue was first identified on February 11, 2019, and DigiCert acknowledged the problem the following day. They implemented a system block to prevent further issuance of these certificates and conducted a thorough investigation. The incident report detailed the timeline of actions taken and the problematic certificates involved.

1. 2019-02-11 Problem identified via Mozilla's security forum.
2. 2019-02-12 DigiCert acknowledged the issue and began investigation.
3. 2019-02-13 System block implemented to halt issuance of non-compliant certificates.