vanmathy cryptography network security

vanmathy cryptography network security

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  NADAR SARASWATHI COLLEGEOF ARTS&SCIENCE,THENI DEPARTMENT OF COMPUTER SCIENCE&INFORMATION TECHNOLOGY V.VANMATHY I-MSC(CS)
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  topic: intruder
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  INTRUDERS  Any setof actions that attempt to compromise the confidentiality, integrity, or availability of a computer resource  One of the most publicized attack to security is the intruder, generally referred to a hacker or cracker. There classes of intruder are as follows:  Masquerader  Misfeasor  Clandestine user
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  INTRUSION DETECTION SYSTEM (IDS)
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  INTRUSION DELECTION SYSTEM(IDS) Intrusion detectionI the process of identifying and responding to malicious activity targeted at resources IDS is a system designed to test/analyze network system traffic/events against a give set of parameters and alert/capture data when these IDS uses collected information and predefined knowledge-based System reason about the possibility of an intrusion. IDS also provides services to cop with intrusion such as giving alarms, activating programs to try to deal with intrusion,etc.
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  FUNCTION OF IDS An IDS detects attacks as soon as possible and takes appropriate action.  An ID dose not usually take preventive measures when an attack is detected  It is a reactive rather than a pro-active agent  It plays a role of informant rather than a police officer.
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  PRINICIPLES OF INTRUCTIONDETECTION SYSTEM  An IDS must run unattended for extended periods of time  The IDS must stay active and secure  The IDS must be also to recognize unusual activity  The IDS must operate without unduly affecting the system’s activity  The IDS must be configurable
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  PRINCIPLES OF INTRUIONDETECTION SYSTEMS
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  COMPONENTS OF IDS Basically there are three components or modules in an intrusion detection system:  Sensor: responsible for capturing packets and sending to the console class.  Console: responsible for analyzing packets captured by enor class.  Its is the class responsible for displaying GUI and generating alerts
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  TYPES OF IDS Network intrusion detection system(INDS)  Protocol based intrusion detection system(PIDS)  Application protocol based intrusion detection system(APIDS)  Host-based intrusion detection system(HIDS)
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  VIRUSES AND RELATED THREATS Perhaps the most sophisticated types of threats to computer systems are presented by program that exploit vulnerabilities in computing systems.  Malicious programs
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  Viruses  Virus-vital informationresources under seize  A virus is a malware program that, when executed, replicates by inserting copies of itself into other computer programs, data files, or the boot sector of the hard drive Virus phases: Dormant-waiting on trigger event Propagation –replicating to programs/disks Triggering-by event to execute payload Execution- of payload
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  TYPES OF VIRUSES
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  VIRUS COUNTERMEASURES Viral attacks exploitlack of integrity control on systems to defend need to add such controls Typically by one or more of:  Prevention-block virus infection mechanism  Detection-of viruses in infected system  Reaction – restoring system to clean state
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  VIRUS REMOVAL TECHIQUE
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  FIREWALL DESIGN PRINCIPLES  Informationsystem undergo a steady evolution (from small LAN’s to internet connectivity).  Strong security features for all workstations and servers not established.  Effective means of protection a local system or network of system from network _ based security threats while affording access to the outside world via WAN’s or the internet.
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  TYPES OF FIREWALLS Three common types of firewalls:  Packet-filtering-router.  Application-level-gateways.  Circuit-level-gateways.  Bastion host
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  TRUSTED SYSTEM  Atrusted system can protect malicious attacks from future bugs or viruses.  The code of a trusted system I passed through rigorous analysis and development  A trusted system and an untrusted system can share a similar foundation
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  TRUSTED SYSTEM MODEL