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WorksheetsNetwork Security Worksheet
Total questions: 40
Worksheet time: 20mins
What is the primary goal of network security?
Improve network speed
Protect data from unauthorized access
Increase bandwidth
Reduce hardware cost
Which component in the network security model represents the entity trying to gain unauthorized access?
Sender
Receiver
Intruder
Trusted third party
In a basic network security model, encryption is applied at the:
Receiver side
Sender side
Intruder side
Firewall
Which of the following ensures confidentiality in network security?
Authentication
Encryption
Access control
Audit trail
The transformation of plaintext into ciphertext is known as:
Compression
Authentication
Encryption
Hashing
Which security service ensures the identity of communicating parties?
Confidentiality
Authentication
Availability
Non-repudiation
Which component manages the keys used in cryptographic communication?
Firewall
Intruder
Key Distribution Center
Router
A passive attack mainly aims at:
Modifying data
Destroying data
Eavesdropping
Blocking service
In symmetric key cryptography, the same key is used for:
Encryption only
Decryption only
Both encryption and decryption
Key generation
Which of the following is a disadvantage of symmetric key encryption?
Slow encryption
Complex algorithms
Key distribution problem
High computation cost
The security of a symmetric cipher primarily depends on:
Ciphertext size
Secrecy of the algorithm
Secrecy of the key
Network speed
Which of the following is an example of symmetric encryption?
RSA
Diffie-Hellman
DES
DSA
In symmetric encryption, the communicating parties must:
Share public keys
Share a secret key
Use digital certificates
Use different keys
Which operation is common in symmetric ciphers?
Digital signature
XOR operation
Key exchange
Hash comparison
Substitution cipher works by:
Reordering plaintext characters
Replacing characters with other characters
Hiding characters
Encrypting images
Which of the following is a monoalphabetic substitution cipher?
Vigenère cipher
Playfair cipher
Caesar cipher
Hill cipher
In Caesar cipher, each letter is shifted by:
1 position
2 positions
A fixed number of positions
Random positions
The total number of possible keys in Caesar cipher is:
26
25
52
Infinite
Which cipher uses a keyword to generate a cipher alphabet?
Caesar cipher
Playfair cipher
Monoalphabetic cipher
Hill cipher
Playfair cipher encrypts plaintext in units of:
Single letters
Digits
Letter pairs
Blocks of 4
Which letter is usually omitted or combined in Playfair cipher?
A
Z
J
X
Which cipher is vulnerable to frequency analysis?
Caesar cipher
Monoalphabetic cipher
Both A and B
Hill cipher
Transposition cipher changes the:
Letters of plaintext
Meaning of message
Order of characters
Key length
In transposition cipher, plaintext characters are:
Replaced
Shifted
Rearranged
Removed
Which of the following is a transposition cipher?
Caesar cipher
Rail Fence cipher
Vigenère cipher
Playfair cipher
Rail Fence cipher is based on:
Substitution
Rearrangement
XOR operation
Hashing
The key in a transposition cipher generally defines:
Character replacement
Number of rounds
Rearrangement pattern
Cipher alphabet
Which cipher combines substitution and transposition?
Caesar cipher
Playfair cipher
Product cipher
Rail Fence cipher
Steganography is the art of:
Encrypting data
Compressing data
Hiding data
Decrypting data
In steganography, the hidden message is called:
Ciphertext
Payload
Plaintext
Key
Which of the following can be used as a cover medium?
Image
Audio
Video
All of the above
Steganography mainly provides:
Confidentiality
Integrity
Availability
Obscurity
Which technique hides data in the least significant bit?
Substitution
LSB technique
Hashing
Transposition
Steganography differs from cryptography because it:
Encrypts data
Hides the existence of data
Uses keys
Requires authentication
Which of the following is a drawback of steganography?
Easy to detect
Limited hiding capacity
High computation cost
Complex keys
Steganalysis is the process of:
Hiding data
Encrypting data
Detecting hidden data
Key generation
Which technique provides both encryption and hiding?
Cryptography only
Steganography only
Both combined
Transposition
Which cipher is most vulnerable to brute-force attack?
Caesar cipher
Hill cipher
Playfair cipher
Product cipher
In network security, a trusted third party is mainly used for:
Encrypting messages
Key management
Data storage
Packet routing
Classical encryption techniques are generally:
Computationally secure
Perfectly secure
Easy to implement but weak
Based on public key systems
