OPERATING SYSTEM SECURITY
24.1 INFORMATION PROTECTION AND SECURITY.
This chapter reviews the principles of security in operating systems. Some general-purpose tools can be built into computers and operating systems (OSs) that support a variety of protection and security mechanisms. In general, the concern is with the problem of controlling access to computer systems and the information stored in them. Four types of overall protection policies, of increasing order of difficulty, have been identified:
- No sharing. In this case, processes are completely isolated from each other, and each process has exclusive control over the resources statically or dynamically assigned to it. With this policy, processes often “share” a program or data file by making a copy of it and transferring the copy into their own virtual memory.
- Sharing originals of program or data files. With the ...