Trusted Hardware Acceleration for Function Secret Sharing

2026-08-17

AI Summary

This work addresses the high computational overhead of Function Secret Sharing (FSS) in privacy-preserving computation by proposing DFA, a distributed FSS accelerator. Integrating an AES engine with programmable units, this architecture introduces a trusted hardware mode enabling on-the-fly key generation to eliminate distribution bottlenecks, alongside an untrusted mode for pure evaluation acceleration. Experimental results demonstrate that DFA reduces secure inference latency by 10×, communication volume by 20×, and energy consumption by over 5×. Furthermore, it achieves a 5× throughput improvement and 10× energy reduction for Private Information Retrieval (PIR). Ultimately, this design significantly enhances the overall efficiency of privacy-preserving systems at moderate hardware costs, effectively mitigating critical performance limitations in current FSS-based applications.

Abstract

Function secret sharing (FSS) is a core building block for privacy-preserving systems such as secure inference and private information retrieval (PIR), but incurs significant overhead in key generation, communication, and data movement.We present the distributed function accelerator (DFA), a hardware accelerator that targets the dominant primitive in FSS: distributed point function (DPF) generation and evaluation. DFA combines a high-throughput fixed-function engine for AES-based pseudorandom number generation with a lightweight programmable unit for protocol-specific logic. In untrusted mode, DFA serves as a pure accelerator for DPF evaluation, improving throughput and energy efficiency without changing the protocol. In trusted mode, it further enables local, on-the-fly key generation, eliminating key distribution, and reducing storage and data movement overheads. Across representative workloads, DFA achieves a reduction of 10X end-to-end latency, a reduction of up to 20X communication and more than 5X energy savings for secure inference; and an improvement of 5X throughput and 10X energy reduction for PIR, with modest hardware cost.

Problem

• Function Secret Sharing
• Privacy-preserving systems
• Secure inference
• Private Information Retrieval
• Performance overhead

Innovation

• Function Secret Sharing
• Hardware Accelerator
• Distributed Point Function
• Trusted Hardware
• Secure Inference