Question

When the Round Constant is given by S[8(r-1)+j]. What are the limits of ‘i’ and ‘j’?

(a) i = 1 ; 0 <= j <= 7

(b) i = 0 ; 0 <= j <= 7

(c) 0 <= i <= 7; 0 <= j <= 7

(d) 0 <= i <= 7; j=0

The question was asked in an interview for internship.

My question comes from Whirlpool Algorithm topic in portion Message Authentication Codes, Whirlpool Algorithm and Key Management and Distribution of Cryptograph & Network Security

Answer 1

Right answer is (b) i = 0 ; 0 <= j <= 7

To explain I would say: All rows except the first one are 0 i.e. RC=0 for ‘i’ not equal to 0.