Wireless Sensor Networks are present in a wide range of environments. The possibility of secure interaction with other networks is a current challenge. It will be necessary that the components of the network can adapt its algorithms (authentication, cryptography) to the requirements of the application in real time. This paper presents a flexible hardware-based approach using partial reconfiguration of an FPGA to modify certain elements of the network nodes. Details about the implementation of reconfigurable security algorithms is presented in this paper to explore the possibilities that this type of devices offer in the design of WSN components.