Updates to IEEE Std 1588™-2019 are provided in this amendment. This amendment also adds guidelines on the application and operation of GDOI (Group Domain of Interpretation) key management to Annex P. and it corrects errors and clarifies statements in 16.4 and Annex P.

This amendment enhances the security option of the IEEE 1588-2019 in the following ways: • Add guidelines on the use of GDOI Key Management with the PTP • Make changes to the standard necessary to support automated key management mechanisms • Fix errors and clarify unclear statements .