I am having some trouble understanding how to calculate the correlation coefficient for CPA attack on AES.
In the article Study of Deep Learning Techniques for Side-Channel Analysis and Introduction to ASCAD Database, they actually keep 700 measurements for the computation of 1 SBox (page 11), in step 7 of the algorithm (page 12).
But when we want to calculate the hamming distance between the input and output of that computation for a guessed subkey, we will get a single value representing the distance. So how will we calculate the coefficient between the measurements and the hamming distance? Since we have 700 measurements for the same instruction, but only one hamming distance.