Access Control
Once a user has been authenticated, the next step is to ensure that they can only access the information
resources that are appropriate. This is done through the use of access control. Access control determines
which users are authorized to read, modify, add, and/or delete information. Several different access control
models exist. Here we will discuss two: the access control list (ACL) and role-based access control
(RBAC).
For each information resource that an organization wishes to manage, a list of users who have the
ability to take specific actions can be created. This is an access control list, or ACL. For each user, specific
capabilities are assigned, such as read, write, delete, or add. Only users with those capabilities are allowed
to perform those functions. If a user is not on the list, they have no ability to even know that the information
resource exists.
ACLs are simple to understand and maintain. However, they have several drawbacks. The primary
drawback is that each information resource is managed separately, so if a security administrator wanted to
add or remove a user to a large set of information resources, it would be quite difficult. And as the number
of users and resources increase, ACLs become harder to maintain. This has led to an improved method of
access control, called role-based access control, or RBAC. With RBAC, instead of giving specific users
access rights to an information resource, users are assigned to roles and then those roles are assigned the
access. This allows the administrators to manage users and roles separately, simplifying administration and,
by extension, improving security.