It consists of a multiplier that computes the auxiliary input sequence, a permutation block that permute the input sequence in an appropriate order and two MUXs and a adder/ subtractor used to obtain the input sequences in the necessary form as shown in equation (10).
As each of dangling nodes and nondangling nodes corresponds to its particular row, one can permute the rows of H and then get P, whose rows corresponding to dangling nodes are all at the bottom:
Since most of the exercises are repeated in semitone intervals, there is adequate opportunity to permute through the basic vowel set /a/, /e/, /i/, /o/, /u/.
This means that we can essentially permute the set of numbers, and measure the success of the attacker by how successful they can be at guessing a specific number given a permuted number and some other defined data.
We can drag the chosen row to be the topmost row, and then permute the columns so that all the non-null entries in the topmost row are in the beginning of the row.