tailieunhanh - Lecture Operating system concepts (Sixth ed) - Chapter 19: Security

The information stored in the system (both data and code), as well as the physical resources of the computer system, need to be protected from unauthorized access, malicious destruction or alteration, and accidental introduction of inconsistency. In this chapter, we examine the ways in which information may be misused or intentionally made inconsistent. We then present mechanisms to guard against this occurrence. | Module 19 Security The Security Problem Authentication Program Threats System Threats Securing Systems Intrusion Detection Encryption Windows NT Operating System Concepts Silberschatz Galvin and Gagne 2002 The Security Problem Security must consider external environment of the system and protect it from unauthorized access. malicious modification or destruction accidental introduction of inconsistency. Easier to protect against accidental than malicious misuse. Operating System Concepts Silberschatz Galvin and Gagne 2002 Authentication User identity most often established through passwords can be considered a special case of either keys or capabilities. Passwords must be kept secret. Frequent change of passwords. Use of non-guessable passwords. Log all invalid access attempts. Passwords may also either be encrypted or allowed to be used only once. Operating System Concepts Silberschatz Galvin and Gagne .