Database Protection

ACCESS CONTROL MECHANISM

INTRODUCTION-

Access Control is any mechanism by which a system grants or revokes the right to access some data, or perform some action. Normally, a user must first Login to a system, using some Authentication system. Next, the Access Control mechanism controls what operations the user may or may not make by comparing the User ID to an Access Control database.

Access Control systems include:

File permissions, such as create, read, edit or delete on a file server.

Program permissions, such as the right to execute a program on an application server.

Data rights, such as the right to retrieve or update information in a database.

TYPES OF ACCESS CONTROL MECHANISM-There are 2 types of access control mechanism-

1. Discretionary access control mechanism

2. Mandatory access control mechanism

1. Discretionary access control mechanism-

• These are used to grant privileges to the user
• Including the capability to access specific data files ,records or fields in a specified mode such as read,insert,delete or update.

2. Mandatory access control mechanism-

• These are used to enforce multilevel security by classifying the data and users into various security classes or levels and then implementing the appropriate security policy of the organization 
• Example- A typical security policy is to permit users at a certain classification level to see only the data items classified at the users own classification level.
• An extension of this is role based security which enforces policies and privileges based on the concept of roles.