In this work, we implement our previously proposed charge-sharing symmetric adiabatic logic (CSSAL) in an 8-bit S-box circuit using a multi-stage positive polarity Reed-Muller (PPRM) representation with a composite field technique. We evaluate the effectiveness of the CSSAL S-box circuit against side-channel attacks towards the variations of the CMOS process technology. The results of this paper are obtained from the SPICE simulation with 0.18-µm and 90-nm standard CMOS technology at an operating frequency band of 125 KHz-70 MHz.