google/heir
Open-source Apache 2.0 compiler for homomorphic encryption. Demo applications include private recommendations, fraud detection, Kitsune network anomaly detection, and hotword detection.
Single-threaded CPU latency numbers published for demos. Community partners include Belfort, Niobium, Cornami, and Optalysys. Four peer-reviewed publications built on HEIR as of August 2026.
Production overhead: independent analysis cites 100x–1000x+ latency vs plaintext inference for FHE workloads.