Consider a System That Supports 5,000 Users. Suppose You Want to Allow 4,990 of Those Users to Be Able to Access One File. How Would You Specify This Protection Scheme in Unix®?

File Protection Scheme: UNIX

Unix is a multiuser operating system that is used on a wide range of machines from powerful microcomputers to supercomputers (Stallings, Chapter 12, 2012). In Unix, permissions can be configured allowing an owner to define different permissions of any file, limiting or granting access where needed. These permissions can be set to various categories such as owner permissions, group permissions, and other permissions. This allows the ability to control various access rights to files. These access rights vary from users not even knowing they exist, to the ability to modify and change them. Access rights can include: none, knowledge, execute, read, appending, update/write, changing protection, and deleting (Stallings, Chapter 12, 2012).

For example, if there are multiple users working on a single site or program, each user can be assigned to certain files and directories, and be limited to what they can do. This provides security to the owner in such a way that their files can safe from unwanted users. In the system, each user is assigned a specific ID. Each ID can be sorted into none or multiple group classes. A specific user ID or a group class can then be assigned to any selected file(s). The group class entry or ID associated with the file(s) are specified the permissions for the file by the owner of that file. Typically, the owner of the file is either the owner of the program or a programmer of the file/directory. These permissions set by the owner of the file(s) (read, write, execute, etc.), represent the maximum permissions that can be assigned to the users of the group (Stallings, Chapter 12, 2012).

An easy way to understand this protection method is by thinking of various access levels. Imagine a system’s files being held in a building with multiple levels. For the purpose of this example, there are 5,000 users in the building. Each of these users is tagged with an ID. On the first level, there are files for all users to...