Computer security basics

Computer security basics

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  Introduction to Computer security By, P.srinu 24
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  COMPUTER SECURITY Why?:to protectthe computing system and protect the data that they store and access  Security attacks :- actions that comprises the computer security  Security mechanisms:-tools such as algorithms, protocols designed to detect ,prevent or recover from a security attack  Security services :-specific kind of protection to the system resources
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  SECURITY THREAT • Threatpotential violation of security and also causes harm. • Vulnerability a weakness that is left unprotected.
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  SECURITY ATTACK Passive attack:gettinginformation from the system ,but it does not affect the system.  analyzing the traffic to find the nature of communication  difficult to detect as they do not involve alteration of the data  Hence better to Prevent rather than Detection
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  Active Attack: triesto alter the system resources or affect its operations.  Masquerade  replay(capture events and replay)  Modifications of messages  Denial of services “Difficult to prevent but can be detected and recovered “
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  TARGET users • identity • privacyof user » eg.pin(personal identification number) of atm,credit card, login id’s, pass codes How ?? tracking of users habits and actions What?? Cookies(cannot install malware) and spam mails are used for attacking
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  Attacks on computerhardware • Natural calamities such as Floods, Earthquakes, power fluctuations. • Destructive actions of burglars or people
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  Attacks on software Aim? toharm the data stored and programs in computer how?? Executables files:- programs written to do harm rather than good What?? malicious software :-a software code included into the system which is harmful in nature Hacking:-intruding into another computer or network to perform an illegal act
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  MALICIOUS SOFTWARE A softwareprogram which is Destructive in nature. Characteristics  can attach itself to other healthy programs.  replicates itself and thus can spread across a network  Infects an executable file or program  Cannot infect write protect disks , hardware, compressed files How dies it harm? • Corrupt or delete data, change functionality of software , erase everything on the hard disk, degrade the system performance. What??  E mail attachment, downloads on internet. Eg. I love you, melissa,Brain, anna kournikova………. VIRU S
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  Java scripts ,javaapplets and Activex controls • Java applets :- it can be part of a web page and executed by the Java Virtual Machine executed by browsers for many platforms, including Microsoft Windows ,Unix, Linux etc. • ActiveX controls:- similar to java applets but do not have security checks • Java scripts:-a scripting language commonly implemented as part of a web browser in order to create enhanced user interfaces and dynamic websites
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  WORMS • Self replicatingsoftware that uses network and security holes • it scans the network of a system and copies itself and then starts replicating from there. • Worm and virus are different • Consumes the resources like bandwidth of computer and makes it slow. E.g. nimda(multiple infectious virus), code red (Chinese),
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  TROJAN HORSE • Itis a destructive program that masquerade as useful program.
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  • The reasonbehind the name is the Greek soldiers who reached the city of troy by hiding in the wooden horse. Similarly games, software etc. can corrupt Data, Programs or damage files
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