The following S-Box is used as part of an encryption algorithm to translate bit
ID: 3767407 • Letter: T
Question
The following S-Box is used as part of an encryption algorithm to translate bit strings of length 4 into bit strings of length 3. The first digit Is used as a row selector and the remaining three bits as the column selector. Construct the corresponding truth table. Evaluate the Hamming distance between each of the binary output rows in sequence from row 0 to row 15. Do the S-Box entries appear to have been the output of a random generation process? If you add the 1's in each column of the output columns in the truth table there are exactly 8 1's. Is that expected? Write down, but do not minimize the Sum of Products (SOP) of the output function for left most bit.Explanation / Answer
b)
c)
NO
reasons:
1) row2 is obtained by reversing row 1
2) hamming distance between input and output is either 1 or 2, where as possible values are 0,1,2,3,4
d)
yes it is expected ,
since if we add all the once of any bit column from 0 to 7(in any order ) , it will come as 4
as we repeated twice
it will come as 8