bellbind

# Basics of Elliptic Curve Cryptography implementation on Python
import collections


def inv(n, q):
    """div on PN modulo a/b mod q as a * inv(b, q) mod q
    >>> assert n * inv(n, q) % q == 1
    """
    for i in range(q):
        if (n * i) % q == 1: