Review the security relevant monitoring-data regularly and, if necessary, reconfigure the monitoring

Organization must document the retention periods for data sets and their possible archiving process (including archiving method, location or destruction). At the end of the retention period, the data must be archived or destroyed without delay in a secure manner.

When destroying data contained in data systems, the following points should be taken into account:

• suitable method of destruction (e.g. overwriting, cryptographic erasure ) is chosen taking into account the functional and statutory requirements
• the need to preserve evidence of data destruction is discussed
• when using third parties for data destruction, the requirement of evidence and the inclusion of destruction requirements in supplier contracts are discussed

The process of archiving or destroying data is defined in connection with the documentation, and the owner of the data is responsible for its implementation.

Continually assess whether the collected data, both security-relevant monitoring data and obtained threat information from relevant sources, is sufficiently relevant and detailed.

Only relevant monitoring data should be collected and preserved, and if necessary, reconfigure the monitoring in line with the strategy. All collected data which no longer has operational or security relevance should be removed.

System logs often contain a wealth of information, much of which is irrelevant to security monitoring. In order to identify events relevant to security monitoring, consideration should be given to automatically copying appropriate message types to another log or to using appropriate utilities or audit tools to review and resolve files.