Security+ Hashing Salting Key Exchange Quiz

1. Why is salt added to passwords before hashing?

To increase the hash output size

To prevent rainbow table attacks and ensure identical passwords produce different hashes

To speed up the hashing process

To make passwords shorter

2. What is a key derivation function (KDF) used for?

To encrypt plaintext directly

To derive multiple cryptographic keys from a single source

To replace hashing in all applications

To authenticate users without passwords

3. What does the Diffie-Hellman key exchange accomplish?

Encrypts data during transmission

Allows two parties to establish a shared secret over an insecure channel

Authenticates the identity of both parties

Verifies data integrity using digital signatures

4. Which property must a cryptographic hash function possess to be secure?

It must be reversible

It must be fast to compute

A small change in input must dramatically change the output

It must produce variable-length outputs

5. What is a collision in hashing?

When two different inputs produce the same hash output

When a hash function fails to process input

When a salt value is reused

When encryption and hashing are used together

6. What does SHA-256 produce as output?

128-bit hash

192-bit hash

256-bit hash

512-bit hash

7. What is the relationship between hashing and digital signatures?

They are identical processes

A hash is created first, then encrypted with a private key for the signature

Digital signatures replace the need for hashing

Hashing is used only for passwords, signatures for documents

8. Which statement correctly describes HMAC (Hash-based Message Authentication Code)?

It provides both encryption and authentication

It combines a hash function with a secret key for authentication

It replaces the need for digital signatures

It is primarily used for password storage

9. What vulnerability does a rainbow table attack exploit?

Weak encryption algorithms

Pre-computed hash values of common passwords

Poor key management practices

Insufficient key length

10. Which algorithm is recommended for secure password hashing in modern applications?

SHA-1

Bcrypt or Argon2

MD5

CRC32

11. What is the primary advantage of elliptic curve cryptography over RSA for key exchange?

It is faster and requires shorter keys for equivalent security

It does not require salting

It provides encryption in addition to key exchange

It is resistant to quantum computing attacks

12. What is the primary purpose of hashing in cryptography?

To encrypt data for confidentiality

To create a fixed-length fingerprint for integrity verification

To exchange keys between two parties

To authenticate users with passwords

13. What is the minimum recommended salt length for password hashing?

4 bytes

8 bytes

16 bytes

32 bytes

14. Which key exchange protocol uses elliptic curve cryptography?

RSA

ECDH

DES

AES

15. How does bcrypt enhance password security compared to plain SHA-256?

It uses a longer hash output

It incorporates salting and a configurable work factor to slow down hashing

It encrypts the password before hashing

It eliminates the need for secure password storage

16. Which hashing algorithm is considered cryptographically broken and should no longer be used?

SHA-256

MD5

SHA-512

BLAKE2

17. Which attack type specifically targets hashed passwords stored in a database?

Man-in-the-middle

Brute force or dictionary attack

SQL injection

Cross-site scripting

18. In the Diffie-Hellman key exchange, what is publicly transmitted between parties?

The shared secret key

Private keys

Public parameters and partial keys

The symmetric encryption key

19. Which key exchange method provides forward secrecy?

Static RSA key exchange

Ephemeral Diffie-Hellman (DHE)

Pre-shared keys

Hardcoded symmetric keys

20. In Perfect Forward Secrecy (PFS), if a long-term key is compromised, what remains secure?

All past and future sessions

Only future sessions

Past session keys are still exposed

Neither past nor future sessions

Security+ Hashing Salting and Key Exchange Concepts Quiz