U3.2 Access Control Structures

Access Control Matrix
1. Based on a grid. Subjects on the side, objects accross
  1. Not practical for large organisations with 100's of subjects and 10000's of objects, to many empty spaces and wasted memory
Access Control List
1. Concentrate on objects
  1. ACL for object is stored within the object
    1. Checked before access is granted
  2. More widely used than Matrix
2. Used by UNIX
3. Main disadvantage is checking the list is time consuming, if access is revoked for a user then every object has to be checked for that user
Capability list
1. Focus on access rights of Subjects
  1. Concentrate on the rows of a matrix
2. Used in databases
3. Disadvantages
  1. difficult to ascertain the rights to an object
  2. difficult to revoke permissions if owner has granted certain rights to subjects
How does the Reference Monitor ascertain which subjects have access to which objects?

Resource summary

	Created by Craig Parker about 11 years ago