SECURITY AND EFFICIENCY FOR MULTI-PARTY COMPUTATION WALLETS

Abstract

Methods, systems, and apparatus for multiplicative to additive share conversions in MPC wallet protocols. In one aspect, a first party generates a graded encoding for a first secret value using a first LWE instance that comprises the first secret value. The first party receives a graded encoding for the second secret value from a second party in possession of a second secret value. The first party computes a product of: the graded encoding for the second secret value, the graded encoding for the first secret value, and a first public matrix generated by or assigned to the first party, where the product comprises a second additive secret value and forms a second LWE instance. The first party inverts the second LWE instance to compute a first additive secret value. The first party performs a cryptographic operation in an MPC wallet protocol using the first additive secret value.

CPC Classifications