@@ -0,0 +1,271 @@
+from abc import ABCMeta, abstractmethod%0A%0A%0Aclass AbstractEncryptor:%0A    __metaclass__ = ABCMeta%0A%0A    @abstractmethod%0A    def encrypt(message):%0A        pass%0A%0A%0Aclass AbstractDecryptor:%0A    __metaclass__ = ABCMeta%0A%0A    @abstractmethod%0A    def decrypt(message):%0A        pass%0A%0A

create abstract classes for a general encryptor and decryptor