Time-Delayed Converter-Reshuffling: An Efficient and Secure Power Delivery Architecture

In this letter, a time-delayed converter-reshuffling (CoRe) technique is proposed as a countermeasure against machine learning based differential power analysis (DPA) attacks where the attacker can synchronize the sampling frequency with the operating frequency of the device under attack. The proposed time-delayed CoRe technique exploits the distributed nature of multiphase switched capacitor voltage converters where half of the converter stages are delayed to eliminate the risk of having zero power trace entropy (PTE) under machine learning based DPA attacks. A high PTE value is maintained (above 3.2 for a 64-phase time-delayed CoRe technique) regardless of the phase difference between the attacker´s sampling rate and the operating frequency. In addition, the minimum PTE value of the proposed time-delayed CoRe technique is enhanced from zero to ~ 3 by inserting a certain time-delay to half of the converter stages.