Ethical Hacking Cryptography and Encryption

Question 1

Which hashing algorithm produces a 128-bit hash and is considered cryptographically broken?

Accepted Answer

MD5

Answer

SHA-256

Answer

SHA-1

Answer

bcrypt

Question 2

What is the difference between symmetric and asymmetric encryption?

Accepted Answer

Symmetric uses the same key for encryption and decryption; asymmetric uses a key pair (public/private)

Answer

Symmetric uses larger keys; asymmetric uses smaller keys

Answer

Symmetric is faster for large keys; asymmetric is faster for small keys

Answer

There is no practical difference in modern cryptography

Question 3

Which attack attempts every possible key combination to decrypt encrypted data?

Accepted Answer

Brute force attack

Answer

Dictionary attack

Answer

Rainbow table attack

Answer

Side-channel attack

Question 4

What is 'key exchange' in cryptography and which protocol is most commonly used?

Accepted Answer

Securely establishing a shared secret over an untrusted channel; Diffie-Hellman

Answer

Distributing symmetric keys via email; PGP

Answer

Storing encryption keys in a hardware module; HSM

Answer

Sharing public keys via certificates; X.509

Question 5

Which cryptographic attack exploits weaknesses in cipher implementation rather than the algorithm itself?

Accepted Answer

Side-channel attack

Answer

Brute force attack

Answer

Dictionary attack

Answer

Birthday attack

Question 6

What is a 'digital certificate' used for in PKI?

Accepted Answer

Binding a public key to an identity, verified by a trusted Certificate Authority

Answer

Storing encrypted passwords securely

Answer

Encrypting network traffic between two endpoints

Answer

Generating one-time passwords for authentication