The model of protection in a computer system can be viewed as an access control

Question

The model of protection in a computer system can be viewed as an access control matrix, with rows
representing objects (for example ?les), and columns representing domains (for example users). Each
entry in the matrix represents the access rights of the domain to the object. Consider the access control
matrix below:


Afile Bfile Cfile Dfile
Anna rwx r x
Bill r rx x
Charles r r rw r
Damian r rw

Assume that each user (domain) is the owner of the ?le (object) with the name starting with their
initial, i.e. Anna owns A?le, Bill owns B?le etc. Represent the access control matrix in the table
above using protection scheme available in UNIX. You will need to de?ne groups of users.

Explanation / Answer

Ideally, the members of a user group live in the same geographic area, so they can get together in person. However, some user groups have members distributed throughout the world, and they meet using Internet chat rooms, message boards, or mailing lists. Members may also correspond by telephone and e-mail on a one-to-one basis. User groups often have Web sites that each member can visit on a regular basis to stay informed. A user group may be devoted to a particular technology, application, or corporation. For example, a digital-photography user group might discuss the assets and limitations of various digital cameras and image-processing programs. A user group devoted to wireless Internet would share their experiences with the various providers of that technology. Some user groups are involved only with the products of a particular corporation. When devoted to a narrow range of products or ideas, the user group is sometimes called a special interest group This section provides information on the following: Background: User Group Profiles in User-Centered Design (UCD) Accessibility Considerations for User Group Profiles Detailed Examples of User Group Profiles

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.