Explore topic-wise MCQs in Operating System.

This section includes 46 Mcqs, each offering curated multiple-choice questions to sharpen your Operating System knowledge and support exam preparation. Choose a topic below to get started.

1.

In _____________________ same keys are implemented for encrypting as well as decrypting the information.

A. Symmetric Key Encryption
B. Asymmetric Key Encryption
C. Asymmetric Key Decryption
D. Hash-based Key Encryption
Answer» B. Asymmetric Key Encryption
2.

DES stands for ________________

A. Data Encryption Security
B. Data Encrypted Standard
C. Device Encryption Standard
D. Data Encryption Standard
Answer» E.
3.

A set of all probable decryption keys are collectively termed as key space.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
4.

_______________ takes the plain text and the key as input for creating cipher-text.

A. Decryption Algorithm
B. Hashing Algorithm
C. Tuning Algorithm
D. Encryption Algorithm
Answer» B. Hashing Algorithm
5.

The ________________ has piece of the keyword that has the same length as that of the plaintext.

A. Block Cipher
B. One-time pad
C. Hash functions
D. Vigenere Cipher
Answer» C. Hash functions
6.

The procedure to add bits to the last block is termed as _________________

A. decryption
B. hashing
C. tuning
D. padding
Answer» E.
7.

__________ cryptography has always been focussing on the concept of ‘security through obscurity’.

A. Modern
B. Asymmetric
C. Classic
D. Latest
Answer» D. Latest
8.

A set of all probable decryption keys are collectively termed as ____________

A. key-stack
B. key bunch
C. key space
D. key pack
Answer» D. key pack
9.

A cryptosystem is also termed as ______________

A. secure system
B. cipher system
C. cipher-text
D. secure algorithm
Answer» C. cipher-text
10.

The process of disguising plaintext in such a way that its substance gets hidden (into what is known as cipher-text) is called _________________

A. cryptanalysis
B. decryption
C. reverse engineering
D. encryption
Answer» E.
11.

_____________ is the concept that tells us about the replacement of every alphabet by another alphabet and the entire series gets ‘shifted’ by some fixed quantity.

A. Rolling Cipher
B. Shift Cipher
C. Playfair Cipher
D. Block Cipher
Answer» C. Playfair Cipher
12.

Data Encryption Standard is implemented using the Feistel Cipher which employs 16 round of Feistel structure.

A. DES
B. IDEA
C. Caesar cipher
D. Twofish
Answer» B. IDEA
13.

______________ employs a text string as a key that is implemented to do a series of shifts on the plain-text.

A. Vigenere Cipher
B. Shift Cipher
C. Playfair Cipher
D. Block Cipher
Answer» B. Shift Cipher
14.

In __________________ 2 different keys are implemented for encrypting as well as decrypting that particular information.

A. Symmetric Key Encryption
B. Asymmetric Key Encryption
C. Asymmetric Key Decryption
D. Hash-based Key Encryption
Answer» C. Asymmetric Key Decryption
15.

In Playfair cipher, at first, a key table is produced. That key table is a 5 by 5 grid of alphabets which operates as the key to encrypt the plaintext.

A. Rolling Cipher
B. Shift Cipher
C. Playfair Cipher
D. Block Cipher
Answer» D. Block Cipher
16.

Which of the following is not a steganography tool?

A. Xaio steganography
B. Image steganography
C. ReaperExploit
D. Steghide
Answer» D. Steghide
17.

People will normally think it as a normal/regular file and your secret message will pass on without any _______________

A. suspicion
B. decryption
C. encryption
D. cracking
Answer» B. decryption
18.

AES is at least 6-times faster than 3-DES.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
19.

____________ carries out all its calculations on bytes rather than using bits and is at least 6-times faster than 3-DES.

A. AES
B. DES
C. IDEA
D. Twofish
Answer» B. DES
20.

Which of the following is not an example of a block cipher?

A. DES
B. IDEA
C. Caesar cipher
D. Twofish
Answer» D. Twofish
21.

____________ is a mono-alphabetic encryption code wherein each & every letter of plain-text is replaced by another letter in creating the cipher-text.

A. Polyalphabetic Cipher
B. Caesar Cipher
C. Playfair Cipher
D. Monoalphabetic Cipher
Answer» C. Playfair Cipher
22.

Which of the following is not a steganography tool ?

A. Crypture
B. SteganographX Plus
C. rSteg
D. Burp Suite
Answer» E.
23.

The method of reverting the encrypted text which is known as cipher text to its original form i.e. plain text is known as ________________

A. cryptanalysis
B. decryption
C. reverse engineering
D. encryption
Answer» C. reverse engineering
24.

By using ______________ you can diminish the chance of data leakage.

A. Cryptography
B. Tomography
C. Chorography
D. Steganography
Answer» E.
25.

The word ________________is a combination of the Greek words ‘steganos’ which means “covered or concealed”, and ‘graphein’ which means “writing”.

A. Cryptography
B. Tomography
C. Steganography
D. Chorography
Answer» D. Chorography
26.

Encryption-decryption in cryptosystem is done in ______ ways.

A. 4
B. 3
C. 5
D. 2
Answer» E.
27.

_____________________ is the art & science of cracking the cipher-text without knowing the key.

A. Cracking
B. Cryptanalysis
C. Cryptography
D. Crypto-hacking
Answer» C. Cryptography
28.

______________ is the mathematical procedure or algorithm which produces a cipher-text for any specified plaintext.

A. Encryption Algorithm
B. Decryption Algorithm
C. Hashing Algorithm
D. Tuning Algorithm
Answer» B. Decryption Algorithm
29.

Cryptography offers a set of required security services. Which of the following is not among that 4 required security services?

A. Encryption
B. Message Authentication codes
C. Hash functions
D. Steganography
Answer» E.
30.

Which of the following is not the primary objective of cryptography?

A. Confidentiality
B. Data Integrity
C. Data Redundancy
D. Authentication
Answer» D. Authentication
31.

The main motive for using steganography is that hackers or other users can hide a secret message behind a ______________

A. special file
B. ordinary file
C. program file
D. encrypted file
Answer» C. program file
32.

A ________________ tool permits security professional or a hacker to embed hidden data within a carrier file like an image or video which can later be extracted from them.

A. Cryptography
B. Tomography
C. Chorography
D. Steganography
Answer» E.
33.

In _______________ the plain-text is processed 1-bit at a time & a series of actions is carried out on it for generating one bit of cipher-text.

A. Block Cipher
B. One-time pad
C. Stream cipher
D. Vigenere Cipher
Answer» D. Vigenere Cipher
34.

In _____________ a sequence of actions is carried out on this block after a block of plain-text bits is chosen for generating a block of cipher-text bits.

A. Block Cipher
B. One-time pad
C. Hash functions
D. Vigenere Cipher
Answer» B. One-time pad
35.

____________________ is a mathematical algorithm that produces a unique plain text for a given cipher text along with a decryption key.

A. Decryption Algorithm
B. Hashing Algorithm
C. Tuning Algorithm
D. Encryption Algorithm
Answer» B. Hashing Algorithm
36.

Steganography follows the concept of security through obscurity.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
37.

_____________ is hiding of data within data, where we can hide images, text, and other messages within images, videos, music or recording files.

A. Cryptography
B. Tomography
C. Steganography
D. Chorography
Answer» D. Chorography
38.

_____________ is another data hiding technique which can be used in conjunction with cryptography for the extra-secure method of protecting data.

A. Cryptography
B. Steganography
C. Tomography
D. Chorography
Answer» C. Tomography
39.

_______________ cryptography deals with traditional characters, i.e., letters & digits directly.

A. Modern
B. Classic
C. Asymmetric
D. Latest
Answer» C. Asymmetric
40.

AES stands for ________________

A. Advanced Encryption Security
B. Advanced Encryption Standard
C. Advanced Encrypted Standard
D. Active Encryption Standard
Answer» C. Advanced Encrypted Standard
41.

________________ is a cipher formed out of substitution where for a given key-value the cipher alphabet for every plain text remains fixed all through the encryption procedure.

A. Polyalphabetic Cipher
B. Caesar Cipher
C. Playfair Cipher
D. Monoalphabetic Cipher
Answer» E.
42.

Data Encryption Standard is an example of a _____________ cryptosystem.

A. conventional
B. public key
C. hash key
D. asymmetric-key
Answer» B. public key
43.

Conventional cryptography is also known as _____________ or symmetric-key encryption.

A. secret-key
B. public key
C. protected key
D. primary key
Answer» B. public key
44.

There are ________ types of cryptographic techniques used in general.

A. 2
B. 3
C. 4
D. 5
Answer» C. 4
45.

WHAT_IS_ROLE_OF_KEY_DISTRIBUTION_CENTER_??$

A. It is used to distribute keys to everyone in world
B. It intended to reduce the risks inherent in exchanging keys
C. all of the mentioned
D. none of the mentioned
Answer» C. all of the mentioned
46.

What is not a role of encryption ?

A. It is used to protect data from unauthorized access during transmission
B. It is used to ensure user authentication
C. It is used to ensure data integrity
D. It is used to ensure data corruption doesn’t happens
Answer» E.