Autonomous energy harvesting sensors present one of the most attractive areas of microelectronics at the moment. They are a part of Internet of Things (IoT) systems so the data need to be protected across transmission. One way for data protection is encryption and the other way is digital signature. However, energy consumption of those systems is increased using protections algorithms, and it should be considered because these are energy harvesting systems. The paper describes the ways in which data encryption and digital signature algorithms can be implemented in resource limited systems based on an 8-bit microcontroller. Alongside the implementation method, the paper deals with the energy demands of the selected encryption algorithms and digital signatures. The execution time, energy consumption, and memory consumption will be considered.

Designing of the vehicle magnetic signature generator is presented in this paper. The basic concept used in designing is distortion of the Earth’s magnetic field that occurs in the presence of ferromagnetic materials. The experimental setup for measuring the magnetic field distortion caused by a vehicle is presented, and based on the obtained values of the magnetic field, input data for signature generator are obtained. The magnetic signature generator consists of a solenoid with a copper wire wound on the bobbin made by the three-dimensional (3D) printer, and an arbitrary function generator RIGOL DG1022Z. Determination of the solenoid parameters and a voltage level of a generator are described thoroughly. In order to demonstrate performances of the generator, magnetic signatures of four different vehicles are generated by proposed design and compared with measured ones by Pearson’s correlation coefficient, indicating a greater correlation than 0.993.