Craig Gentry

Gentry’s construction of fully homomorphic encryption (FHE) transformed the cryptographic landscape by proving that arbitrary computation on encrypted data is theoretically possible. That result catalyzed a wave of research into practical and hybrid privacy technologies—work that ARPA’s architects had to evaluate when selecting MPC as their primary mechanism. FHE offers different trade‑offs (stronger on‑ciphertext computation guarantees but historically high performance costs), whereas MPC provides interactive protocols with distinct scalability and trust assumptions. The development of FHE pushed the community to optimize underlying number‑theoretic operations, noise‑management techniques, and engineering approaches that have spillover benefits for MPC implementations (for example, in polynomial arithmetic, batching, and parallelization). For ARPA, the existence and maturation trajectory of FHE influenced system design discussions about which workloads to keep off‑chain, how to architect interoperability with on‑chain verification, and when a hybrid FHE‑MPC design could improve both performance and confidentiality. Gentry’s breakthrough therefore indirectly shaped ARPA’s research choices, comparative evaluations and roadmap for cryptographic primitives.