1. Information flow

In IT security, the object of all covetousness is information. The key concept here is information flow. This is a security policy that defines the way in which information flows through the system. The aim of such a policy is to ensure the confidentiality and/or integrity of the information, i.e. that only authorized persons have access to the information, and that the information is not modified in any abnormal way.

In an attempt to achieve these objectives, system administrators often apply various measures that resemble a heap of patches: setting up backups, advanced password management, applying security patches, adding access control mechanisms, and so on.