Certified Ethical Hacker (CEH v13) — Question 95

This form of encryption algorithm is a symmetric key block cipher that is characterized by a 128-bit block size, and its key size can be up to 256 bits. Which among the following is this encryption algorithm?

Answer options

• A. HMAC encryption algorithm
• B. Twofish encryption algorithm
• C. IDEA
• D. Blowfish encryption algorithm

Correct answer: B

Explanation

The correct answer is B, Twofish encryption algorithm, as it meets the criteria of being a symmetric key block cipher with a 128-bit block size and supports key sizes up to 256 bits. A is incorrect because HMAC is not an encryption algorithm; it's a message authentication code. C and D are also incorrect as IDEA and Blowfish do not have the specified block and key size characteristics.