Question

What is a block cipher algorithm that operates on 64-bit blocks and can have a key length from 32 to 448 bits?

Answer 1

The question has the below multiple choices

A) 3DES
B) RSA
C) Blowfish
D) Twofish

The answer is (C) Blowfish

Also known as the Blow-CAST-Fish, it was designed to run efficiently on 32 bit computers. Up to date no significant weaknesses have been seen. Based on Blow-CAST-Fish, it uses good features of CAST -128[6] algorithms and Blowfish [1]. Features taken from Blowfish [1] algorithm include; S-box entries which are key dependent substitution, varying key lengths of up to 448 bits and procedure of Key expansion