mSIGNIA’s PaySim is an end-to-end payment simulation platform. mSIGNIA’s Payment Simulator (or PaySim) is a complete, end-to-end payment simulation platform for testing compliance and interoperability including enabling 3rd-party product demonstration for various payment initiatives such as EMV 3D-Secure versions 2.1 and 2.2, SCA, FIDO, and W3C related Web Authentication and Payment.