8.7 Ensure Signing Keys are Unique

Information

Each zone should have a unique Zone Signing Keys (ZSK) and a unique Key Signing Keys (KSK) that is different from all other keys.

Rationale:

The ZSK key typically has a shorter expiration date then the KSK, and should be unique from the KSK as well as keys used for other zones. If a private key is compromised, the damage is limited to unique key that was disclosed, rather the compromising multiple zones.

Solution

To remediate a duplicate key, perform the following:

Generate a new key to replace the duplicate key using dnssec-keygen and one of the recommended algorithms. An example command is shown below:

# dnssec-keygen -a ECDSAP256SHA256 example.org

Implement a rollover period to phase out the duplicate key and replace it with the the newly generated key.

Once the key is fully deleted from the active use, remove the file.

See Also

https://workbench.cisecurity.org/files/2997

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-13

Plugin: Unix

Control ID: d182d4d10cf9e3e7204885f4d52eaa823c14b44d2f0affe90826d04e9ea5c1a8