1. What is plaintext?

A. the original intelligible message or data that is fed into the algorithm as input.

B. the original intelligible message or data that is produced as output.

C. the scrambled message produced as output.

D. the scrambled message or data that is fed into the algorithm as output.

E. None of the statements

2. What is encryption algorithm?

A. Performs various substitutions and transformations on the plaintext

B. Performs various substitutions and transformations on the ciphertext

C. It takes the ciphertext and the secret key and produces the original plaintext.

D. the scrambled message produced as output.

E. random stream of data and, as it stands, is unintelligible.

3. If you encrypt a ciphertext using right key, you will get:

A. Plaintext

B. Gibberish

C. Error message

D. Ciphertext

E. Key

4. One objective of cryptography is keeping information secret from all but those who are authorised to see it. The term referring to this is:

A. Anonymity

B. Authorisation

C. Confidentiality

D. Secrecy

E. Witnessing

5. One objective of cryptography is ensuring information has not been altered by unauthorised or unknown means. The term referring to this is:

A. Authorisation

B. Confirmation

C. Data integrity

D. Message authentication

E. Validation

6. One objective of cryptography is identifying and acknowledging the identity of entity. The term referring to this is:

A. Confirmation

B. Identification

C. Message authentication

D. Validation

E. Witnessing

7. One objective of cryptography is conveyance, to another entity, of official sanction to do or be something. The term referring to this is:

A. Authorisation

B. Certificate

C. Confirmation

D. Entity authentication

E. Validation

8. If a wrong key is entered to decrypt a message, what will happen?

A. Nothing will happen

B. The output will be gibberish

C. The output will not be visible

D. There is an error message

E. The cryptosystem will stop working

9. Which of these statements is TRUE?

A. The term “key” comes from the fact that the password you choose works in the same way that a conventional key works.

B. In cryptography, to protect the contents of your files, you install a lock (a decryption algorithm) on your door (the computer).

C. The encryption algorithm performs its steps using the key to alter the ciphertext and convert it to plaintext.

D. In symmetric-key cryptography, the key that is used to encrypt data is the same key that is used to decrypt it.

E. The decryption algorithm performs its steps using the key to alter the plaintext and convert it to ciphertext.

10. What is Encryption algorithm?

A. the original intelligible message or data that is fed into the algorithm as input

B. performs various substitutions and transformations on the plaintext

C. the scrambled message produced as output

D. takes the ciphertext and the secret key and produces the original plaintext

E. None of the statements are true

11. What is Decryption algorithm?

A. the original intelligible message or data that is fed into the algorithm as input

B. performs various substitutions and transformations on the plaintext

C. the scrambled message produced as output

D. takes the ciphertext and the secret key and produces the original plaintext

E. None of the statements are true

12. A _______ cipher replaces one character with another character

A. Substitution

B. Transposition

C. Multiplication

D. Reversing

E. Cultivation

13. Which of the following is not a fundamental security goal?

A. Confidentiality

B. Integrity

C. Assurance

D. Availability

E. All of the statements are correct

14. ______________ is the science and art of transforming messages to make them secure and immune to attacks.

A. Cryptography

B. Cryptoanalysis

C. Confidentiality

D. Cryptosystem

E. None of the statements

15. A combination of an encryption algorithm and decryption algorithm is called a _________ ?

A. Cipher

B. Secret

C. Key

D. Polyalphabetic cipher

E. Substitution

16. The _______________ is a number or a set of numbers on which the cipher operates.

A. Cipher

B. Secret

C. Plaintext

D. Key

E. Ciphertext

17. The Caesar cipher is a __________ cipher that has a key of 3.

A. Transposition

B. Additive

C. Shift

D. Subtractive

E. Multiplicative

18. Which of the following(s) is(are) form(s) of malware(malicious software)?

A. Viruses

B. Scripts

C. Rootkits

D. Worms

E. All of the statements are correct.

19. What does a firewall do?

A. Scans for viruses on your system

B. Checks floppy or CDs for corrupted files

C. Protects against power surges

D. Protects your computer from Internet intrusion

E. Restores lost data on your computer

20. You can use ____________ to protect your computer from outsiders.

A. Antivirus software and personal firewall programs

B. System restore and antivirus software

C. Personal firewall programs and system restore

D. Antivirus software and the Recycle Bin

E. Firewall programs and the Recycle Bin

21. A stateful firewall maintains a ______________, which is a list of active connections.

A. Routing table

B. Bridging table

C. State table

D. Connection table

E. Hub table

22. A _________-level proxy inspects the entire packet and makes access decisions based on the contents of the packet.

A. Circuit

B. Application

C. Proxy

D. Server

E. Physical

23. A datagram is called ______ at the physcial layer of OSI.

A. Bits

B. Segments

C. Frames

D. Packets

E. Bytes

24. A(n) ________ is a fancy term for a computer that has two network interfaces/

A. Proxy gateway

B. Duel-homed host

C. Routing workstation

D. NAT server

E. None of the statements

25. _____________ is another term for a packet of digital information.

A. Footer

B. Header

C. Data

D. Datagram

E. Bits

26. Some _________ firewalls are able to examine the contents of packets as well as the headers for signs that they are legitimate.

A. Boundary

B. Stateful

C. Stateless

D. Personal

E. DMZ

27. What is one advantage of setting up a DMZ with two firewalls?

A. You can control where traffic goes in the three networks

B. You can do stateful packet filtering

C. You can do load balancing

D. Improved network performance

E. All of the statements

28. Possibility of an incident or attack to cause damage to your enterprise

A. Risk

B. Virus

C. Security

D. Assets

E. Malware

29. One objective of cryptography is prevention of authorized access to resources or the delaying of time-critical operations.

A. Authentication

B. Denial of service

C. Availability

D. Reliability

E. Confidentiality

30. One objective of cryptography is property of being accessible and useable upon demand by an authorized entity.

A. Authentication

B. Denial of service

C. Availability

D. Reliability

E. Confidentiality

31. ________________ is a form of cryptosystem in which encryption and decryption are performed using two different keys, one a public key and one a private key.

A. Asymmetric encryption

B. Symmetric encryption

C. Synchronous encryption

D. Asynchronous encryption

E. None of the statements

32. Which of the following statement(s) is(are) ingredients for a public-key encryption scheme?

A. Plaintext

B. Encryption/Decryption algorithm

C. Public/Private keys

D. Ciphertext

E. All of the statements

33. A pair of keys that have been selected so that if one is used for encryption, the other is used for decryption in Public-Key Cryptosystem.

A. Public and private keys.

B. Public and cipher keys.

C. Plain and cipher keys.

D. Encryption and decryption keys.

E. None of the statements.

34. Match each term according to their meanings in Public-Key Cryptosystem

Plaintext:

This is the readable message or data that is fed into the algorithm as input.

Encryption algorithm:

The encryption algorithm performs various transformations on the plaintext.

Public and private keys:

This is a pair of keys that have been selected so that if one is used for encryption, the other is used for decryption. The exact transformations performed by the algorithm depend on the public or private key that is provided as input.

Ciphertext:

This is the scrambled message produced as output. It depends on the plaintext and the key. For a given message, two different keys will produce two different ciphertexts.

Decryption algorithm:

This algorithm accepts the ciphertext and the matching key and produces the original plaintext.