What is access Control

There are many type of access control such as :
- access control for computers.
- access control for machine.
- access control for doors.
- access control for area.
An important requirement of any information management system is to protect data
and resources against unauthorized disclosure (secrecy) and unauthorized or improper
modifications (integrity), while at the same time ensuring their availability to legitimate
users (no denials-of-service). Enforcing protection therefore requires that every access
to a system and its resources be controlled and that all and on ly authorized accesses can
take place. This process goes under the name of access control. The development of an
access control system requires the definition of the regulations according to which access is to be controlled and their implementation as functions executable by a computer
system. The development process is usually carried out with a multi-phase approach
based on the following concepts:
Security policy: it defines the (high-level) rules according to which access control
must be regulated.1
Security model: it provides a formal representation of the access control security policy and its working. The formalization allows the proof of properties on the security
provided by the access control system being designed.