Differential power analysis countermeasures

An electronic device includes a plurality of logic units, which have respective inputs and outputs and are arranged in a ring topology, such that an input of each of the logic units is coupled to an output of another of the logic units. Each of the logic units includes respective processing logic, which is identical to and operates in synchrony with the processing logic of the other logic units to process respective data values using at least one secret value stored in the device. The logic units are coupled, at an initial cycle of the device, to receive respective input values that are mutually uncorrelated. At subsequent cycles of the device, each of the logic units receives and operates on intermediate values that are output by another of the logic units.