Time Stamps | Synchronization With Authoritative Time Source, v1.0

Defines conformance and assessment criteria for verifying that an information system compares and synchronizes internal system clocks with an organization-defined authoritative time source. .
If an assessment step references organization-defined elements (E.g. <organization-defined personnel or roles>, <organization-defined frequency>, etc.), corresponding citations/excerpts must be provided to confirm that the organization has established and documented these values and that they apply as referenced in the conformance criteria.

Similarly, if a "Selection" among multiple options (e.g. [Selection (one or more): as needed; ]) is specified, evidence must be provided to establish that the option(s) implemented by the organization have been defined and documented.

The assessment step shall not be marked as satisfied without this evidence.

Assessment Step

1
Time Stamps | Synchronization With Authoritative Time Source (TimeStampsSynchronizationWithAuthoritativeTimeSource)
Does the information system: (a) Compare the internal information system clocks [Assignment: organization-defined frequency] with [Assignment: organization-defined authoritative time source]; and (b) Synchronize the internal system clocks to the authoritative time source when the time difference is greater than [Assignment: organization-defined time period]?
Artifact
A1
Provide evidence (e.g. organizational policies, procedures, compliance/assessment reports, etc.) that support the assessor's response to this assessment step.
Parameter
Synchronization Frequencyrequired
NUMBER : Provide the frequency (in hours) at which the system synchronizes its clocks with an authoritative time source.
If conformance criteria reference organization-defined elements (e.g. <organization-defined personnel or roles>, <organization-defined frequency>, etc.), these values must be defined and documented by the organization.

Similarly, if the criteria specify a "Selection" among multiple options (e.g. [Selection (one or more): as needed; ]), the option(s) implemented by the organization must also be defined and documented.

Conformance Criteria (1)

C1
The information system: (a) Compares the internal information system clocks [Assignment: organization-defined frequency] with [Assignment: organization-defined authoritative time source]; and (b) Synchronizes the internal system clocks to the authoritative time source when the time difference is greater than [Assignment: organization-defined time period].
Citation
SP800-53R4
Appendix F, AU-8 (1)