Explain 'audit and accountability' requirements under advanced system security measures which are applied to high criticality systems.

'Audit and Accountability' requirements under advanced system security measures, which can be applied to high criticality systems, are given as under: Enable process auditing or accounting: Enable process auditing or accounting, which generates log information about the creation of new processes and their system activity. Audit privilege escalation or change in privilege: Generate a log message whenever a user changes their level of privilege. Audit firewall denial: Generate a log message when the host-based firewall denies a network connection. Audit all significant application events: Log all significant application events. Write audit events to a separate system: System logs must be written to a remote system in such a way that they cannot be altered by any user on the system being logged.