  We present a multi-language, cross-platform, open-source library for
asymmetric private set intersection (PSI) and PSI-Cardinality (PSI-C). Our
protocol combines traditional DDH-based PSI and PSI-C protocols with
compression based on Bloom filters that helps reduce communication in the
asymmetric setting. Currently, our library supports C++, C, Go, WebAssembly,
JavaScript, Python, and Rust, and runs on both traditional hardware (x86) and
browser targets. We further apply our library to two use cases: (i) a
privacy-preserving contact tracing protocol that is compatible with existing
approaches, but improves their privacy guarantees, and (ii) privacy-preserving
machine learning on vertically partitioned data.
