In-memory computation in homomorphic encryption systems

Abstract

In an approach, a process stores a matrix of multibit values for a computation in an analog multiply-accumulate unit including at least one crossbar array of binary analog memory cells connected between respective pairs of word- and bit-lines of the array, where: bits of each multibit value are stored in cells connected along a word-line, and corresponding bits of values in a column of the matrix are stored in cells connected along a bit-line. In each of one or more computation stages for a cryptographic element, the process supplies a set of polynomial coefficients of an element bitwise to respective word-lines of the unit to obtain analog accumulation signals on the respective bit-lines. The process converts the analog signals to digital. The process processes the digital signals obtained from successive bits of the polynomial coefficients in each of the stages to obtain a computation result for the cryptographic element.