SYSTEM AND METHOD FOR SWITCHED-CAPACITOR BASED SIDE-CHANNEL COUNTERMEASURES

Methods and systems are provided for a charge withholding converter reshuffling technique that decorrelates input power of a multi-phase switched capacitor (SC) voltage converter relative to the output power provided to a load. The load may be a cryptographic device. The technique provides a countermeasure against power analysis attacks. A controller including a first random number generator coupled to the stages of the SC voltage converter controls gating for charging a first subset of the stages. A controller including a second random number generator coupled the stages of the SC voltage converter controls gating for discharging a second subset the stages. A number of the switched capacitor stages maintain their charge beyond the switch period in which they are charged. The SC voltage converter withholds a random portion of input charge and delivers this charge to the load after a random time period.