Operating System Concepts, 8th Edition

CHAPTER 15

Security

 

15.1 The Security Problem

15.2 Program Threats

15.3 System and Network Threats

15.4 Cryptography as a Security Tool

15.5 User Authentication

15.6 Implementing Security Defenses

15.7 Firewalling to Protect Systems and Networks

15.8 Computer-Security Classifications

15.9 An Example: Windows XP

15.10 Summary

Exercises

Wiley Plus

Bibliographical Notes

 

Protection, as we discussed in Chapter 14, is strictly an internal problem: How do we provide controlled access to programs and data stored in a computer system? Security, on the other hand, requires not only an adequate protection system but also consideration of the external environment within which the system operates. A protection system is ineffective if user authentication is compromised or a program is run by an unauthorized user.

Computer resources must be guarded against unauthorized access, malicious destruction or alteration, and accidental introduction of inconsistency. These resources include information stored in the system (both data and code), as well as the CPU, memory, disks, tapes, and networking that are the computer. In this chapter, we start by examining ways in which resources may be accidentally or purposely misused. We then explore a key security enabler

• cryptography. Finally, we look at mechanisms to guard against or detect attacks.

CHAPTER OBJECTIVES

• To discuss security threats and attacks.

• To explain the fundamentals of encryption, authentication, and hashing.

• To examine the uses ...