SC-31 Covert Channel Analysis

With each revision to SP 800-53, minor adjustments may occur with the security control baselines including, for example, allocating additional controls and/or control enhancements, eliminating selected controls/enhancements, and changing sequencing priority codes (P-codes). These changes reflect: (i) the ongoing receipt and analysis of threat information; (ii) the periodic reexamination of the initial assumptions that generated the security control baselines; (iii) the desire for common security control baseline starting points for national security and non-national security systems to achieve community-wide convergence (relying subsequently on specific overlays to describe any adjustments from the common starting points); and (iv) the periodic reassessment of priority codes to appropriately balance the workload of security control implementation. Over time, as the security control catalog expands to address the continuing challenges from a dynamic and growing threat space that is increasingly sophisticated, organizations will come to rely to a much greater degree on overlays to provide the needed specialization for their security plans.