1. HTTPS ensures security by using:
Correct Answer: a) TLS/SSL encryption
Explanation: HTTPS (HTTP Secure) uses TLS (Transport Layer Security) or its predecessor SSL to encrypt all communication between client and server, protecting against eavesdropping and tampering.
2. Which protocol is used for secure email communication?
Correct Answer: a) PGP (Pretty Good Privacy)
Explanation: PGP provides end-to-end email encryption using public-key cryptography. Modern alternatives include S/MIME and GPG (GNU Privacy Guard).
3. A man-in-the-middle (MITM) attack can be prevented by:
Correct Answer: a) Digital certificates and TLS
Explanation: TLS with proper certificate validation ensures server authenticity and encrypts communications, preventing MITM attackers from intercepting or modifying data.
4. Which port is used for secure web browsing (HTTPS)?
Correct Answer: a) 443
Explanation: Standard ports: HTTP (80), HTTPS (443), FTP (21), SMTP (25). Modern browsers now enforce HTTPS by default and warn about insecure HTTP connections.
5. Symmetric encryption uses:
Correct Answer: a) Same key for encryption and decryption
Explanation: Symmetric encryption (AES, DES) is fast but requires secure key exchange. Asymmetric (public-key) encryption uses key pairs but is slower.
6. Which is a strong encryption algorithm?
Correct Answer: a) AES-256
Explanation: AES-256 is a modern symmetric encryption standard. DES is obsolete (too short keys), while MD5 and SHA-1 are hashes (not encryption) and cryptographically broken.
7. Public-key cryptography is used for:
Correct Answer: a) Secure key exchange (e.g., Diffie-Hellman)
Explanation: Public-key crypto enables secure key exchange (ECDH), digital signatures (RSA, ECDSA), and encryption (RSA). It's too slow for bulk data encryption.
8. Which of the following is INSECURE for password storage?
Correct Answer: a) Plaintext in a database
Explanation: Passwords must be hashed with salt using memory-hard functions (Argon2 > bcrypt > PBKDF2). Plaintext storage exposes all passwords if breached.
9. Regular password changes are recommended ONLY if:
Correct Answer: a) There's suspicion of compromise
Explanation: NIST guidelines now recommend against periodic password changes unless compromise is suspected, as they often lead to weaker passwords (e.g., "Summer2023!", "Summer2024!").
10. A password manager helps by:
Correct Answer: a) Generating and storing strong, unique passwords
Explanation: Password managers (Bitwarden, 1Password) create/store complex passwords encrypted with a master password, solving password reuse and weak password problems.
11. Phishing attacks can be mitigated by:
Correct Answer: a) Verifying sender email addresses
Explanation: Check for: mismatched sender domains, suspicious links (hover before clicking), urgent/unnatural language. MFA also helps prevent account takeover if credentials are phished.
12. Which is a secure alternative to FTP?
Correct Answer: a) SFTP (SSH File Transfer Protocol)
Explanation: SFTP encrypts both commands and data over SSH (port 22). Alternatives: FTPS (FTP over SSL, port 990) or SCP. Plain FTP (port 21) sends credentials and data in clear text.