remember for the range proof, you have a set of points (C1, C2, ..., C8) where C1 = 1 or 0, C2 = 2 or 0, ... C8 = 8 or 0, so that when you add up those points, you get another point D that it's value is the sum of those points or (v1 + v2 + v3 ...) G so you know it's in range
