Certified Ethical Hacker Cryptography Fundamentals 2

Question 1

Which encryption type uses the same key for both encryption and decryption?

Accepted Answer

Symmetric encryption

Answer

Symmetric encryption uses a single shared secret key for both operations.

Question 2

What is the key size used by the AES algorithm in its strongest standard configuration?

Accepted Answer

256 bits

Answer

AES supports 128, 192, and 256-bit keys, with 256-bit being the strongest.

Question 3

Which of the following is a stream cipher?

Accepted Answer

RC4

Answer

RC4 is a stream cipher that encrypts data one bit or byte at a time.

Question 4

In asymmetric cryptography, which key is used to encrypt a message sent to a recipient?

Accepted Answer

The recipient's public key

Answer

Messages are encrypted with the recipient's public key so only their private key can decrypt them.

Question 5

What property of a hash function ensures it is computationally infeasible to find two inputs producing the same output?

Accepted Answer

Collision resistance

Answer

Collision resistance means two different inputs should not produce the same hash value.

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