The Internet of Things is a novel paradigm that is rapidly gaining ground in the scenario of modern wireless telecommunications. However, security of IoT systems is considered as one of the most important challenges facing system developers. The proposed design is a power adaptive encryption solution that provides four different encryption configurations which are AES-256, AES-192, AES-128, and DES. The IoT device can switch between the four configurations depending on the available power budget for encryption. The design uses Partial Dynamic Reconfiguration (PDR) technology to allow the switching between the four configurations using minimal area and power consumption. The proposed design was tested on a ZedBoard development board after being synthesized using Xilinx Vivado.