In this paper, we propose secure and intuitive device authentication techniques for the Smart Grid enabled Home Area Networks (HANs). We assume a distributed architecture for the HAN in which the smart appliances can communicate both with the smart meter and the gateway. Further, operating schedules of the smart appliances are controlled by the gateway based on the pricing and control messages from the smart meter. We propose three different authentication mechanisms for devices in the HAN: (1) between the gateway and the smart meter, (2) between the smart appliances and the HAN, and (3) between the transient devices and the HAN. We show that the proposed mechanisms are resilient against insider attackers performing serious attacks such as man-in-the-middle or impersonation during device authentication. Further, the proposed authentication mechanisms are intuitive and require no (or minimum) user effort.