Paper 2021/054

The Cost of IEEE Arithmetic in Secure Computation

David W. Archer and Shahla Atapoor and Nigel P. Smart

Abstract

Programmers are used to the rounding and error properties of IEEE double precision arithmetic, however in secure computing paradigms, such as provided by Multi-Party Computation (MPC), usually a different form of approximation is provided for real number arithmetic. We compare the two standard variants using for LSSS-based MPC, with an implementation of IEEE compliant double precision using binary circuit-based MPC. We compare the relative performance, and conclude that the addition cost of IEEE compliance maybe too great for some applications. Thus in the secure domain standards bodies may wish to examine a different form of real number approximations.