Tamper Resistance Evaluation Method for Energy Harvester

Energy harvesting has been attracted attention for Internet of Things. From the viewpoint of security, data encryption for energy harvester is very important. On the other hand, the threat of side-channel attacks for a cryptographic circuit, which reveal the secret key using the physical information such as power consumption or electromagnetic wave, is pointed out. This study proposes a new tamper resistance evaluation method to secure energy harvester in the future. In experiments, an actual energy harvester, which consists of a TWELITE microcontroller and a silicon based solar cell, was used, and a lightweight cipher TWINE was implemented as an encryption technique. Then, experimental results by the proposed method revealed the 7 partial keys out of 8 with 900 electromagnetic waveforms, and the tamper resistance was successfully evaluated.