Question

Which of the following statements are true with respect to the blowfish algorithm –

i) Provided key is large enough, brute-force key search is not practical, especially given the high key schedule cost

ii) Key dependent S-boxes and sub keys make analysis very difficult

iii) Changing both halves in each round increases security

iv) Blowfish has improved avalanche effects

(a) i) ii) and iv)

(b) ii) and iii)

(c) i)

(d) All are true

This question was posed to me in examination.

This is a very interesting question from Blowfish Algorithm in chapter Pseudorandom Number Generation and Stream Ciphers and More Block Ciphers of Cryptograph & Network Security

Answer 1

The correct option is (d) All are true

To elaborate: All of the above statements are true with respect to the blowfish algorithm.