Bell games normally certify nonlocality by requiring two devices that cannot communicate. Compiling these games under cryptographic assumptions replaces physical separation with computational constraints, so a single untrusted device suffices. The new preprint studies this setting for bipartite games and focuses on quantitative quantum soundness—that is, bounding how much a quantum prover can cheat.
The authors use the sequential NPA hierarchy, a family of relaxations for analyzing quantum strategies, to obtain soundness bounds. The abstract notes that Kalai et al. (STOC'23) already showed that such compilation works; this paper appears to refine the guarantees by making them quantitative rather than merely qualitative.