Cryptography Unit V

System Level Security

Unit - V

1.What is an intruder?
A person who accessing a network in unauthorized manner is called as intruder.

2.What is intrusion detection system?
Intrusion detection system is a system for detection of unauthorized access to the system.

3.What are audit reports? Give its two forms.
Audit report is a fundamental tool for intrusion detecting. Two forms of audit records are
1. Native audit records.
2. Detective specific audit records

4.Define password protection.
Password protection is the format line protection against intruder to the system. A password authenticates the ID and provides security to the system.

5.Define malicious program.
A program that is intentionally included or inserted in a system for harmful purpose is malicious program.

6.What is a Virus?
A virus is piece of program code that can infect other programs by modifying them.

7.What is a worm?
A worm is a program designed to copy itself and send copies from a computer to other computer across the network.

8.What is a Trojan horse?
A Trojan horse is a computer program that appears to be useful but that actually does damage.

9.What is logic bomb?
A logic bomb is software embedded in some legitimate programs and is set to explode under certain conditions.

10.Enlist types of Viruses.
1. Parasitic Virus.
2. Memory resident virus.
3. Boot sector virus
4. Stealth virus.
11.What are the steps in virus removal process?
1. Detection of virus
2. Identification of virus
3. Removal of traces of virus.

12.What is generic decryption technology?
A generic decryption technology can detect most complex polymorphic viruses with fast scanning speed.

13.What is denial of service?
A denial of service is an attempt to prevent a genuine user of service from using it.

14.What are the design goals of firewalls?
1. All the traffic must pass through it.
2. Only authorized traffic is allowed to pass.
3. Firewall itself is immune to penetration.

15.Enlist commonly used firewalls from threats of security.
1. Packet filtering router.
2. Application level gateway.
3. Circuit level gateway.

16.Mention the classes of Intruders.
1. Masquerader: An unauthorized user who prevents a system access control and exploit a user account.
2. Misfeasor: A user who misuses his privileges.
3. Clandestine user: A user who seizes supervisory control of system to suppress audit collection.

17.List out the generations of antivirus technique?
1. First generation- Simple scanners
2. Second generations – Heuristic scanners
3. Third Generations – Activity traps and
4. Fourth Generations – Full featured protection

18.List out the advanced antivirus techniques?
Techniques are:
1. Generic Decryption Technology
2. Digital immune system.
19. Mention the techniques to control access and enforce the security policy?
1. Service control
2. Direction control
3. User control and
4. Behavior control.

20.What do you mean by trusted system?
A trusted system is a computer and operating system that can be verified to implement a given security policy. Typically, the focus of a trusted system is data access control. A policy is implemented that dictates what objects may be accessed.

Part-B
Unit – V

1.Explain in detail about password management system.
2.Explain the various kinds of viruses and how they act on systems and files in detail.
3.Explain in detail, intrusion detection mechanisms and its types.
4.Explain in detail, the various antivirus software mechanism used against the virus threat.