'Return a raw string representation of the object\'s protocol state.
The length of the returned representation is exactly 64 bytes; a
multiple of AES\' 16-byte block size.  That makes it suitable to be
encrypted using AES-CBC.'

def __repr__(self):

    return (((struct.pack('I', self.issueDate) + self.identifier) + self.masterKey) + self.pad)
