Data Protection and Security

V

Access Control

V.I

Introduction

There are two main types of access control:

1. Discretionary Access Control
2. Mandatory Access Control

In discretionary access control, it is the owner of the object who controls other subjects' accesses to the object. For instance in the access control widely implemented in standard multi-user platforms such as Unix and Windows NT , each object is owned by a user and this use can specify for each object, which other users can have which form of access.

In mandatory access control, access to data objects is controlled to prevent flows of information that violate a security policy. In more sophisticated forms of mandatory access control, the system maintains security labels for objects ( fi les) as well as subjects (processes, users). Access is granted or denied based on the se. Mandatory access controls enforce security policies without the cooperation of users or application programs. Such mechanisms are implemented today in special operating system versions for military users.