id: "SC-45(02)" title: "Secondary Authoritative Time Source" family: "SC" family_name: "System and Communications Protection" sort_id: "sc-45.02" priority: "P1" implementation_level: "system" parent: "SC-45" enhancement: True


Identify a secondary authoritative time source that is in a different geographic region than the primary authoritative time source; and

Synchronize the internal system clocks to the secondary authoritative time source if the primary authoritative time source is unavailable.

Guidance

It may be necessary to employ geolocation information to determine that the secondary authoritative time source is in a different geographic region.

Assessment Objective: a secondary authoritative time source is identified that is in a different geographic region than the primary authoritative time source;

Assessment Objective: the internal system clocks are synchronized to the secondary authoritative time source if the primary authoritative time source is unavailable.

System and communications protection policy

procedures addressing time synchronization

system design documentation

system configuration settings and associated documentation

system audit records

system security plan

other relevant documents or records

System/network administrators

organizational personnel with information security responsibilities

organizational personnel installing, configuring, and/or maintaining the system

Mechanisms supporting and/or implementing system time synchronization with secondary authoritative time sources