Q.1 What is the primary purpose of cryptography in network security?
To compress data for faster transmission
To protect information by transforming it into unreadable format
To increase network speed
To manage IP addresses
Explanation - Cryptography ensures confidentiality by encoding data so that only authorized users can access it.
Correct answer is: To protect information by transforming it into unreadable format
Q.2 Which of the following is a symmetric key encryption algorithm?
RSA
AES
DSA
Diffie-Hellman
Explanation - AES (Advanced Encryption Standard) uses the same key for encryption and decryption, making it symmetric.
Correct answer is: AES
Q.3 Which protocol is commonly used to secure web traffic?
HTTP
FTP
HTTPS
SMTP
Explanation - HTTPS adds SSL/TLS encryption to HTTP, securing data transmitted over the web.
Correct answer is: HTTPS
Q.4 What is the main difference between symmetric and asymmetric encryption?
Symmetric uses one key; asymmetric uses two keys
Symmetric is slower than asymmetric
Asymmetric does not use keys
There is no difference
Explanation - Symmetric encryption uses a single shared key, while asymmetric uses a public-private key pair.
Correct answer is: Symmetric uses one key; asymmetric uses two keys
Q.5 Which of the following is a common hashing algorithm?
AES
SHA-256
RSA
Diffie-Hellman
Explanation - SHA-256 generates a fixed-length hash of data, commonly used for data integrity verification.
Correct answer is: SHA-256
Q.6 What does a digital signature provide?
Encryption of the message
Authentication and integrity
Faster data transmission
Compression of files
Explanation - Digital signatures verify the sender's identity and ensure that the message has not been altered.
Correct answer is: Authentication and integrity
Q.7 Which attack involves intercepting and altering communication between two parties?
Phishing
Man-in-the-Middle
DoS
Brute Force
Explanation - A Man-in-the-Middle attack occurs when an attacker secretly relays and possibly alters communication between two parties.
Correct answer is: Man-in-the-Middle
Q.8 Which of the following is a type of malware?
Trojan
HTTPS
SSL
IPSec
Explanation - A Trojan is a malicious program disguised as legitimate software to infiltrate systems.
Correct answer is: Trojan
Q.9 In network security, what is the purpose of a firewall?
To store passwords securely
To filter incoming and outgoing network traffic
To encrypt emails
To speed up the network
Explanation - Firewalls monitor and control network traffic based on security rules, preventing unauthorized access.
Correct answer is: To filter incoming and outgoing network traffic
Q.10 Which encryption method is considered more secure for modern applications?
DES
AES
ROT13
Caesar Cipher
Explanation - AES is widely used today due to its strong security and efficiency compared to older algorithms like DES.
Correct answer is: AES
Q.11 What does SSL/TLS provide in secure communications?
Data integrity, encryption, and authentication
Data compression
Network routing
File transfer speed
Explanation - SSL/TLS ensures that data is encrypted, authenticates servers, and maintains integrity during transmission.
Correct answer is: Data integrity, encryption, and authentication
Q.12 Which of the following is a public-key cryptography algorithm?
AES
RSA
SHA-1
MD5
Explanation - RSA uses a public-private key pair for encryption and decryption, making it asymmetric.
Correct answer is: RSA
Q.13 What type of attack tries every possible key to decrypt a message?
Brute Force Attack
Phishing Attack
Man-in-the-Middle Attack
SQL Injection
Explanation - A brute force attack systematically checks all possible keys until the correct one is found.
Correct answer is: Brute Force Attack
Q.14 Which security principle ensures that data is not altered during transmission?
Confidentiality
Integrity
Availability
Authentication
Explanation - Integrity ensures that data remains unmodified and trustworthy during communication.
Correct answer is: Integrity
Q.15 Which protocol is used for secure remote login to a network device?
Telnet
SSH
FTP
HTTP
Explanation - SSH (Secure Shell) encrypts login sessions, making remote access secure compared to Telnet.
Correct answer is: SSH
Q.16 Which type of malware restricts access to data until a ransom is paid?
Ransomware
Spyware
Adware
Rootkit
Explanation - Ransomware encrypts victim data and demands payment for decryption keys.
Correct answer is: Ransomware
Q.17 In asymmetric cryptography, what is shared publicly?
Private key
Public key
Symmetric key
Session key
Explanation - The public key is shared openly, while the private key is kept secret for decryption.
Correct answer is: Public key
Q.18 Which of the following ensures non-repudiation in digital communications?
Hashing
Digital Signatures
VPN
Firewall
Explanation - Digital signatures prevent the sender from denying the authenticity of a message.
Correct answer is: Digital Signatures
Q.19 Which attack targets the availability of a network or service?
DoS Attack
Phishing
Sniffing
Keylogging
Explanation - Denial-of-Service (DoS) attacks flood a network or server, making it unavailable to legitimate users.
Correct answer is: DoS Attack
Q.20 Which of the following is a common method to ensure data confidentiality?
Encryption
Data replication
Packet sniffing
Load balancing
Explanation - Encryption converts data into unreadable form for unauthorized users, protecting confidentiality.
Correct answer is: Encryption
Q.21 Which cryptographic algorithm is considered obsolete due to security vulnerabilities?
AES
DES
RSA
SHA-256
Explanation - DES (Data Encryption Standard) has small key size and is vulnerable to brute-force attacks, making it obsolete.
Correct answer is: DES
Q.22 Which network security mechanism detects and prevents unauthorized access or attacks?
Intrusion Detection System (IDS)
DNS
HTTP
SMTP
Explanation - IDS monitors network traffic to identify and respond to suspicious activities or attacks.
Correct answer is: Intrusion Detection System (IDS)
Q.23 What is a one-way function in cryptography often used in password storage?
Hash function
Symmetric encryption
Digital signature
VPN
Explanation - Hash functions are one-way, making it infeasible to reverse the process and recover the original input.
Correct answer is: Hash function
Q.24 Which of the following is an example of multi-factor authentication?
Password only
Fingerprint and PIN
Username only
CAPTCHA only
Explanation - Multi-factor authentication requires more than one method, such as something you know (PIN) and something you have/are (fingerprint).
Correct answer is: Fingerprint and PIN
Q.25 What is the main goal of a VPN (Virtual Private Network)?
To increase download speed
To provide secure encrypted communication over public networks
To filter spam emails
To compress data
Explanation - VPNs create secure, encrypted tunnels between devices and networks over the Internet.
Correct answer is: To provide secure encrypted communication over public networks