With today’s technology, several applications accept the existence of tiny devices that may exchange data and type communication networks. In a big portion of such applications, the confidentiality and integrity of the communicated messages are of specific interest. During this work, we tend to propose 2 novel techniques for authenticating short encrypted messages that are directed to fulfill the wants of mobile and pervasive applications. By taking advantage of the very fact that the message to be authenticated should even be encrypted, we tend to propose incontrovertibly secure authentication codes that are a lot of economical than any message authentication code within the literature. The key plan behind the projected techniques is to utilize the safety that the cryptography formula will give to style a lot of economical authentication mechanisms, as against victimization standalone authentication primitives.