EncFormer: Secure and Efficient Transformer Inference Over Encrypted Data

Summary

EncFormer is a two-party framework for private Transformer inference that combines fully homomorphic encryption (FHE) and secure multiparty computation (MPC). It adds Stage-Compatible Patterns to reduce repacking and FHE–MPC conversions, plus a secure complex CKKS–MPC conversion protocol. On GPT- and BERT-style models, it reports 1.4×–30.4× lower inference-time communication and 1.3×–9.9× lower end-to-end latency than prior hybrid FHE–MPC systems.