聊城大学计算机学院计算机操作系统（1）英文课件 Chapter16.pptVIP

Security Chapter 16 Types of Threats Interruption An asset of the system is destroyed of becomes unavailable or unusable Attack on availability Destruction of hardware Cutting of a communication line Disabling the file management system Types of Threats Interception An unauthorized party gains access to an asset Attack on confidentiality Wiretapping to capture data in a network Illicit copying of files or programs Types of Threats Modification An unauthorized party not only gains access but tampers with an asset Attack on integrity Changing values in a data file Altering a program so that it performs differently Modifying the content of messages being transmitted in a network Types of Threats Fabrication An unauthorized party inserts counterfeit objects into the system Attack on authenticity Insertion of spurious messages in a network Addition of records to a file Computer System Assets Hardware Threats include accidental and deliberate damage Software Threats include deletion, alteration, damage Backups of the most recent versions can maintain high availability Computer System Assets Data Involves files Security concerns fro availability, secrecy, and integrity Statistical analysis can lead to determination of individual information which threatens privacy Computer System Assets Communication Lines and Networks – Passive Attacks Learn or make use of information from the system but does not affect system resources Traffic analysis Encryption masks the contents of what is transferred so even if obtained by someone, they would be unable to extract information Computer System Assets Communication Lines and Networks – Passive Attacks Release of message contents for a telephone conversion, an electronic mail message, and a transferred file are subject to these threats Computer System Assets Communication Lines and Networks – Passive Attacks Traffic analysis Encryption masks the contents of what is transferred so even if obtained by someone, they would be unable to