CSCl pre board solutions

6th semester


Answer :-

  1. Why is message authentication code used?

Ans: In cryptography, a message authentication code (MAC), sometimes known as a tag, is a short piece of information used to authenticate a message—in other words, to confirm that the message came from the stated sender (its authenticity) and has not been changed.

  1. Define IPsec

Ans: Internet protocol security (IPsec) is a set of protocols that provides security for Internet Protocol. It can use cryptography to provide security. IPsec can be used for the setting up of virtual private networks (VPNs) in a secure manner. It is also known as IP Security.

  1. List the factor you consider while choosing strong password

Ans:  Dictionary words, Reverse Dictionary words, Account Name Surrounded by delimiters, Dictionary words followed by digits.

  1. Define improper choice of operands and operation

Ans: It is common security related programing problems. It describes preventing errors of choosing the wrong operands or operation requires that the algorithms be thought through carefully.

  1. Define antivirus

Ans: A antivirus is a software designed to detect and destroy computer viruses In other words, Antivirus software is a type of utility used for scanning and removing viruses from your computer. … Since new viruses are constantly being created by computer hackers, antivirus programs must keep an updated database of virus types.

  1. Define host-based information gathering agent

Ans: A host-based intrusion detection system (HIDS) is an intrusion detection system that is capable of monitoring and analyzing the internals of a computing system as well as the network packets on its network interfaces, similar to the way a network-based intrusion detection system (NIDS) operate

  1. List the limitation of SMTP

Ans:Transmission of binary files using SMTP is not possible without converting into text fille.

  • Limited to 7-bit ASCII character only
  • SMTP servers may reject mail message beyond some specific length
  1. Define plagiarism

Ans: Plagiarism is the illicit reproduction of another person’s intellectual property, especially written content, for presentation as one’s own. The definition of the term is often expanded to include not just verbatim copying but also “close imitation
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Masquerading is the process in which user uses a fake identity to get unauthorized access to personal information through legitimate access information.
DMZor demilitarized zone is a physical or logical subnetwork that contains and exposes an organization’s external-facing services to an untrusted network, usually a larger network such as the Internet.
Every signed message from A to B goes to an arbiter BB that everybody trusts BB checks the signature and the timestamp, origin, content, etc. BB dates the message and sends it to B with an indication that it has been verified and it is legitimate. This process is called arbitrated digital signature.
Web securityis important to keeping hackers and cyber-thieves from accessing sensitive information. Without a proactive security strategy, businesses risk the spread and escalation of malware, attacks on other websites, networks, and other IT infrastructures.
This principle requires that the default access to an object is none. Whenever access, privileges, or some security-related attribute is not explicitlygranted, it should be denied.
Common forms of cyberbullying

  • Harassment
  • Flaming
  • Exclusion
  • Outing
  • Masquerading

Various intellectual property rights

  • Copyrights
  • Patents
  • Trademarks

Answer :-

  1. Define IPsec?
  • IPsec, also known as the Internet Protocol Security or IP Security protocol, defines the architecture for security services for IP network traffic. IPsec describes the framework for providing security at the IP layer, as well as the suite of protocols designed to provide that security, through authentication and encryption of IP network packets
  1. List the factor you consider while choosing strong password?
  • Passwords should be long, strong, and complex.
  • Password should not be easy to guess.
  • You should use a different password for every account.
  • Use two-factor authentication when available.
  1. Define antivirus?
  • Antivirus software is a program or set of programs that are designed to prevent, search for, detect, and remove software viruses, and other malicious software like worms, trojans, adware, and more.
  1. List the limitation of SMTP?
  • Only uses NVT 7bit ASCII format
  • No authentication mechanisms
  • Message are sent un-encrypted
  • Susceptible to misuse
  1. Define Plagiarism?
  • To steal and pass off ideas or words of another as one’s own”. Simply put, plagiarism is the process of taking other people’s words and/or ideas and pretending that they are your own.

1) What is computer worm?

  • A computer wormis a standalone malware computer program that replicates itself in order to spread to other computers.

2) More the key space, more secure the cipher algorithm. Explain

  • More the key space, more secure the cipher algorithm because cipher algorithm helps to convert cipher text into plain text due to more space hacker cannot think about so, it is more secure.

3) What is virtual machine?

  • A virtual machine (VM) is a software program or operating system that not only exhibits the behavior of a separate computer, but is also capable of performing tasks such as running applications and programs like a separate computer.

4) What is VPN?

  • A VPN refers to Virtual Private Network is a connection method used to add security and privacy to private and public networks, like WiFi Hotspots and the Internet.

5) What is plagiarism?

  • Plagiarism is the act of taking credit for someone else’s words or ideas. It’s an act of intellectual dishonesty, and it comes with serious consequences.

6) What is intrusion?

  • An intrusion is an unwelcome interruption or a situation where somewhere private has an unwelcome visit or addition.

7) Why ETA was issues?

  • ETA was issues for make legal provision for authentication and regulation and also for controlling unauthorized access of electronic record.

8) Define inference control.

  • Inference control is a mechanism to confine the information content of data or behavior made accessible to or being observable by a participant to whom some pieces of information should be kept confidential.

9) Define digital forensic.

  • Digital forensics is a branch of forensic science and the process of uncovering and interpreting electronic data.

10) What is digital signature? List out two algorithm to get digital signature.

  • Digital Signature is a process that guarantees that the contents of a message have not been altered in transit. The server, digitally sign a document, you add a one-way hash (encryption) of the message content using your public and private key pair.


Define integrity and confidentiality. (Chapter 1)
Integrity refers to guarding against improper modification or destruction of information including ensuring information non repudiation and authenticity.
Confidentiality refers to preserving authorized restrictions on information access and disclosure, including means for protecting personal privacy and proprietary information.

  1. What do you mean by threat, attack and attacker? (Chapter 1)

Threat is a potential violation of security, which exist when there is circumstances, capability, action or event that can be breach a security and cause harm. Attack is an attempt done to obtain, alter, remove or misuse information without authorized access or permission. Attacker can be define as the person who does the activities related to attack in which the person is not authorized.

  1. What is message digest 5(MD5)? Why is it used? (Chapter 2)

MD5 is an algorithm that is used to verify data integrity through the creation of 128 bit from data input that is claimed to be as unique to that specific data.
It can be used as digital signature mechanism which takes message of variable length and produce output of 128 bit message digest.

  1. What do you mean by firewall? List out its type. (Chapter 3)

Firewall is the host that mediates access to a network, by allowing and disallowing certain types of access on the basis of a configured security policy.
Its types are:

  • Packet filtering firewall
  • State full packet filtering
  • Application level / proxy
  • Circuit level gateway
  1. Differentiate between authentication and authorization? (Chapter 4)

Authorization is the granting of privilege that enable a user to have a legitimate access to a system. Whereas authentication is a mechanism that determines whether a user is who he or she claims to be.

  1. What is digital certificate? (Chapter 4)

Digital certificate are electronic credential that are used to certify or validate the online identities of the user, organization and computers.

  1. Define principle of open design? (Chapter 5)

The principle of open design state that the security of a mechanism should not depend on the secrecy of its design and implementation. It suggest that complexity does not add security.

  1. Differentiate between computer worm and virus? (Chapter 6)

Computer worm is a standalone computer program that replicates itself in order to spread to other computers. Computer virus is a program that inserts itself into one or more files and then performs undesirable action.

  1. What do you mean by intruder? List out its types. (Chapter 7)

An intruder is a person who attempts to gain unauthorized access to a system, to damage the system or to disturb the data in the system.
Its types are:

  • Masquerader
  • Misfeasor
  • Clandestine User
  1. Define cybercrime and digital forensic. (Chapter 10)

Cybercrime is a criminal activity done through computer and networks as means of tools to commit offense.
Digital forensic is the process of uncovering and interpreting electronic data and preserving evidence in its most original form while performing a structural investigation through digital information for reconstructing past.

  • Define DMZ.

Ans: a DMZ (demilitarized zone) is a physical or logical sub-network that separates an internal local area network (LAN) from other untrusted networks, usually the Internet. External-facing servers, resources and services are located in the DMZ so they are accessible from the Internet but the rest of the internal LAN remains unreachable.

  • What do you mean by message authentication code(MAC)?

Ans: MAC is a message digest created with a key which Creates security by requiring a secret key to be possesses by both parties in order to retrieve the message.

  • What do you mean by Masquerading?

Ans: masquerade is a type of attack where the attacker pretends to be an authorized user of a system to gain access to it.

  • What is VPN?

Ans:VPN stands for virtual private network. A virtual private network (VPN) is programming that creates a safe, encrypted connection over a less secure network, such as the public internet. A VPN uses tunneling protocols to encrypt data at the sending end and decrypt it at the receiving end.

  • Define Inference Control.

Ans: INFERENCE CONTROL is a control used in the output of databases to stop a person who has access to only summary information from being able to determine (infer) a particular value for a particular record.

  • Differentiate between computer security and digital forensics.

Ans: Cyber security is the process of protecting and defending information systems from threats such as the misuse of systems, attackers, data theft, malware outbreaks, and system outage whereas Digital forensics (sometimes known as digital forensic science) is a branch of forensic science encompassing the recovery and investigation of material found in digital devices, often in relation to computer crime.

  • What do you mean by copyright and plagiarism?

Ans: A copyright is a law that gives the owner of a written document, musical composition, book, picture, or other creative work, the right to decide what other people can do with it. Plagiarism is copying another person’s ideas, words or writing and pretending that they are one’sown work. It can involve violating copyright laws.

  • What do you mean by cyber crime?

Ans: Cybercrime, refers to any crime that involves a computer and a network.The computer may have been used in the commission of a crime, or it may be the hacking, phishing etc.

  • Define payment processing.

Ans: It is usually a third-party service that is actually a system of computer processes that process, verify, and accept or decline credit card transactions on behalf of the merchant through secure Internet connections.

  • Define Notation of trust.

Ans: The effectiveness of any security mechanism depends on the security of the underlying base on
which the mechanism is implemented and the correctness of the implementation. If the trust in the base or in the implementation is misplaced, the mechanism will not be secure. Thus “secure,” like “trust,” is a relative notion, and the design of any mechanism for enhancing computer security must attempt to balance the cost of the mechanism against the level of security desired and the degree of trust in the base that the site accepts as reasonable.
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  1. What is malicious logic?

Malicious logic is defined as any instructions which may cause a site’s security policy to be violated. This typically includes applications which surreptitiously perform harmful actions on behalf of a subject. This paper focuses on Trojan Horses, various types of computer viruses, and worms.

  1. What is PGP?

Pretty Good Privacy (PGP) is a methodology used for encrypting and decrypting digital files and communications over the Internet. PGP provides data/file integrity services by digitally signing messages, allowing receivers to learn whether or not message confidentiality is compromised.
iii. Define Security Vulnerability
Vulnerability is a cyber-security term that refers to a flaw in a system that can leave it open to attack. A vulnerability may also refer to any type of weakness in a computer system itself, in a set of procedures, or in anything that leaves information security exposed to a threat.
iv.List different types of IDS.
A network intrusion detection system (NIDS)
Host intrusion detection systems (HIDS)
Signature-based intrusion detection systems
v.What is computer security CIA traid?
Confidentiality, integrity and availability, also known as the CIA triad, is a model designed to guide policies for information security within an organization. The elements of the triad are considered the three most crucial components of security.
vi.What is TLS?
Transport Layer Security (TLS) is a protocol that provides authentication, privacy, and data integrity between two communicating computer applications. It’s the most widely-deployed security protocol used today and is used for web browsers and other applications that require data to be securely exchanged over a network, such as web browsing sessions, file transfers, VPN connections, remote desktop sessions, and voice over IP (VoIP).
vii.Define message security services.
Message security services is the practice of encrypting messages on your device so that they can be read only by the intended recipient.
ix.Define MAC
Mandatory Access Control (MAC) is is a set of security policies constrained according to system classification, configuration and authentication.It defines and ensures a centralized enforcement of confidential security policy parameters.
x.What is SSL?
SSL (Secure Sockets Layer) is the standard security technology for establishing an encrypted link between a web server and a browser. This link ensures that all data passed between the web server and browsers remain private and integral.