2-Phase Adiabatic Logic for Low-Energy and CPA-Resistant Implantable Medical Devices

Abstract

Designing a low-energy and secure lightweight cryptographic coprocessor is the primary design constraint for modern wireless Implantable Medical Devices (IMDs). The lightweight cryptographic ciphers are the preferred cryptographic solution for low-energy encryption. This article proposes 2-SPGAL, the 2-phase sinusoidal clocking implementation of Symmetric Pass Gate Adiabatic Logic (SPGAL) for IMDs. The proposed 2-SPGAL is energy-efficient and secure against the Correlation Power Analysis (CPA) attack. The proposed 2-SPGAL was evaluated with the integration of synchronous resonant Power Clock Generators (PCGs): (i) 2N2P-PCG, and (ii) 2N-PCG. The case study implementation of one round of PRESENT-80 encryption using 2-SPGAL, with 2N2P-PCG integrated into the design, shows an average of 47.50% of energy saving compared to its CMOS counterpart, over the frequency range of 50 kHz to 250 kHz. The same 2-SPGAL based case study, with 2N-PCG integrated into the design, shows 51.18% of an average energy saving compared to its CMOS counterpart, over 50 kHz to 250 kHz. Further, the 2-SPGAL based PRESENT-80 one round shows an average energy saving of 16.62% and 28.90% respectively for 2N2P-PCG and 2N-PCG integrated into the design compared to existing 2-phase adiabatic logic called 2-EE-SPFAL. We also subjected PRESENT-80 design of 2-SPGAL and CMOS against CPA attack. The 2-SPGAL, with 2N2P-PCG and 2N-PCG, integrated into one round of PRESENT-80 design protects the encryption key. However, the encryption key was successfully revealed in one round of PRESENT-80 design using CMOS logic. Therefore, the proposed 2-SPGAL logic can be useful to design energy-efficient and CPA resilient Implantable Medical Devices (IMDs).