'Performs blinding on the message using random number \'r\'.
:param message: the message, as integer, to blind.
:type message: int
:param r: the random number to blind with.
:type r: int
:return: the blinded message.
:rtype: int
The blinding is such that message = unblind(decrypt(blind(encrypt(message))).
See https://en.wikipedia.org/wiki/Blinding_%28cryptography%29'

def blind(self, message, r):

    return ((message * pow(r, self.e, self.n)) % self.n)
