Multiple choice questions and answers (MCQs) on Computer Security to prepare for exams, tests, and certifications. These questions are taken from a real written exam and some parts are taken from an interview. So you will find questions on basic techniques such as encryption, signature, certificates, authentication, and more. This MCQ will easily prepare anyone to pass their exam.
1. ______ is a program that can infect other programs by modifying them. This modification includes a copy of the virus program, which can then infect other programs.
A Worm
B Virus
C Zombie
D Trap doors
B
A virus is a type of malicious software (malware) consisting of small pieces of code associated with legitimate programs. When this program is run, the virus is executed.
2. ______ are used in denial-of-service (DOS) attacks, usually against targeted websites.
A Worm
B Virus
C Zombie
D Trojan horse
C
A zombie is a computer that has been implanted with a demon that puts it under the control of a malicious hacker without the knowledge of the computer owner. Zombies are used by malicious hackers to launch denial-of-service attacks.
3. The type of encoding in which the manipulation of bit stream without taking into account the meaning of bits is called _________?
A Destination Encoding
B Entropic Encoding
C Source Encoding
D Differential Encoding
B
Entropic encoding is a type of lossless encoding. Huffman encoding is a type of entropy encoding. Entropy encoding appears everywhere in modern digital systems. It is an essential part of data compression, which is generally necessary, especially for the Internet, video, audio, communication, etc.
4. What is the protocol used to secure emails?
A POP
B PGP
C SNMP
D HTTP
B
PGP is used to sign, encrypt and decrypt text, email, files, directories and entire disk partitions, as well as to enhance the security of email communications.
5. The art of breaking ciphers is known as ____?
A Cryptology
B Cryptography
C Cryptanalysis
D Encryption
C
Cryptanalysts seek to decrypt cipher texts without knowing the source of the plaintext, the encryption key, or the algorithm used to encrypt it; Cryptanalysts also targets secure hashing, digital signatures, and other cryptographic algorithms.
6. Which of the following statements is correct?
A Integer – represented by ASCII
B Character – represented by the complement of two
C Character – represented by Unicode
D Character – represented by a complement
C
Unicode is a character encoding standard published by the Unicode Consortium. Computers store numbers that represent a character. Unicode provides a unique number for each character.
7. The number of subkeys generated in the IDEA algorithm is _______?
A 54
B 48
C 52
D 50
C
IDEA (International Data Encryption Algorithm) uses 52 subkeys each of 16 bits. Two are used in each turn, and four are used before each turn and after the last turn. It has eight towers.
(6 * 8 = 48 + 4 = 52 in total) are used in both encryption and decryption processes.
8. The number of “S-boxes” used in the DES algorithm is _______?
A 4
B 8
C 16
D 32
B
In cryptography, S-box (substitution-box) is a basic component of symmetric key algorithms that performs a substitution. In block ciphers, they are usually used to hide the relationship between the key and the ciphertext.
9. ______ is an example of a public key algorithm.
A RSA
B DES
C IREA
D RC5
A
RSA is an algorithm used to encrypt and decrypt messages. It is an asymmetric cryptographic algorithm. Asymmetric means that there are two different keys. This is also called public key cryptography, because one of the keys can be given to anyone.
10. The Caesar cipher is represented by _______?
A C = (p + 3) mod3
B C = (p + 26) mod3
C C = (p – 3) mod26
D C = (p + 3) mod26
A
Caesar’s cipher is one of the earliest known ciphers. It is a type of substitution cipher in which each letter is replaced by another letter.
MCQPractice competitive and technical Multiple Choice Questions and Answers (MCQs) with simple and logical explanations to prepare for tests and interviews.Read More
