15.02 Cryptography And Data Protection - Quiz

Check your understanding

1. What is the fundamental difference between hashing and encryption?

   • Hashing is faster than encryption
   • Hashing is reversible, encryption is not { data-correct }
   • Hashing is one-way, encryption is reversible
   • Hashing uses keys, encryption doesn’t

2. When should you use hashing instead of encryption for password storage?

   • When you need to recover the original password
   • When you only need to verify if a password is correct { data-correct }
   • When the password is less than 8 characters
   • When using symmetric encryption

3. What is the purpose of adding salt to password hashes?

   • To make passwords taste better
   • To increase password length
   • To prevent rainbow table attacks { data-correct }
   • To encrypt the hash value

4. Which of these demonstrates the avalanche effect in hashing?

   • Large inputs create large hashes
   • Small input changes create completely different hashes { data-correct }
   • Hash functions are irreversible
   • Hashes have fixed output lengths

5. What type of encryption should you use for large files?

   • Asymmetric encryption (RSA)
   • Symmetric encryption (AES) { data-correct }
   • Hash-based encryption
   • Password-based encryption only

6. Why can’t RSA encryption handle large amounts of data directly?

   • RSA is too slow for large data
   • RSA has mathematical limitations on input size { data-correct }
   • RSA keys are too small
   • RSA doesn’t support binary data

7. What is the primary purpose of key rotation in cryptographic systems?

   • To improve performance
   • To reduce storage requirements
   • To limit exposure if keys are compromised { data-correct }
   • To make systems more complex

8. Which approach is recommended for deriving encryption keys from passwords?

   • Simple hash function (SHA-256)
   • Password-Based Key Derivation Function (PBKDF2) { data-correct }
   • Base64 encoding
   • XOR operation

9. What should you do with deprecated encryption keys?

   • Delete them immediately
   • Keep them temporarily for data recovery needs { data-correct }
   • Convert them to hash functions
   • Use them for less sensitive data

10. In the password manager example, why is the master password not stored?

    • To save storage space
    • To prevent unauthorized access if the vault is compromised { data-correct }
    • Passwords are automatically generated
    • The system uses biometric authentication

11. What is the correct order for secure password storage?

    • Password → Hash → Salt
    • Password → Salt → Hash { data-correct }
    • Salt → Password → Hash
    • Hash → Password → Salt

12. Why should cryptographic keys have expiration dates?

    • To force users to change passwords
    • To comply with regulations only
    • To limit the time window for potential key compromise { data-correct }
    • To reduce computational overhead

13. What is the advantage of using PBKDF2 over simple hashing for passwords?

    • PBKDF2 produces shorter hashes
    • PBKDF2 is faster to compute
    • PBKDF2 deliberately slows down brute force attacks { data-correct }
    • PBKDF2 doesn’t require salts

14. When building a secure system, which principle should guide key management?

    • Use the same key for all operations
    • Generate keys manually for better control
    • Use separate keys for different purposes { data-correct }
    • Store all keys in the application code

15. What does the secrets.compare_digest() function prevent in password verification?

    • Hash collisions
    • Timing attacks { data-correct }
    • Salt reuse
    • Key derivation errors