Fair MPC ⇒ MPC

Fully-black-box reduction · standard model · folklore · security loss: none

Statement

A protocol that securely computes $f$ with complete fairness against $t$ corruptions (fairness) securely computes $f$ with abort against $t$ corruptions (MPC) — folklore.

Sketch

The simulator for the ideal execution with abort runs the fair simulator; where the fair simulator aborts before the outputs are computed, it submits arbitrary inputs and aborts once it receives the corrupted parties’ outputs, which it discards, so the honest parties output $\perp$ in both cases — standard.