def evaluate(coefs,x):

	res=0

	xK=1

	for a in coefs:

		res^=ffmul(a,xK)

		xK=ffmul(xK,x)

	return res

import os

import gf256

def shareByte(secretB,k,n):

	assert n<255

	coefs=[int(secretB)]+[int(b) for b in os.urandom(k-1)]

	points=[gf256.evaluate(coefs,i) for i in range(1,n+1)]

	return points

def generate(secret,k,n):

	shares=[shareByte(b,k,n) for b in secret]

	return [(i+1, [s[i] for s in shares]) for i in range(n)]

print(generate(b"key",2,3))