6 Authorization
6.1 Authorization model

Authorization models (Fig. 5.1) are used to control access rules to the system (or object) and its services, defined by security system. Basic authorization models are [11]:

- Discretionary Access Control (DAC) – allows the system (or object) owner define who can or cannot access the system
- Mandatory Access Control (MAC) – user access is defined via classifications.
- Role-Based Access Control (RBAC) – the most frequently used. Users are divided into groups with defined role. User can access system based on the role.
- Task Based Access Control (TBAC) – in this model is counter for number of user’s access to the system. If defined value is reached, the next access is rejected.
- Attribute based Access Control (ABAC) – to control access users attributes are used.

All mentioned models can be combined.

Fig. 5.1 – Authorization model