fromeccimportPrivateKey, Signature, G, NfromrandomimportrandintclassPrivateKey(PrivateKey):
defsign(self, z):
# we need a random number k: randint(0, 2**256)# r is the x coordinate of the resulting point k*G# remember 1/k = pow(k, N-2, N)# s = (z+r*secret) / k# return an instance of Signature:# Signature(r, s)pass