Paper 2023/1147 Original: eprint.iacr.org/2023/1147 ↗

CipherGPT: Secure Two-Party GPT Inference

Abstract

ChatGPT is recognized as a significant revolution in the field of artificial intelligence, but it raises serious concerns regarding user privacy, as the data submitted by users may contain sensitive information. Existing solutions for secure inference face significant challenges in supporting GPT-like models due to the enormous number of model parameters and complex activation functions. In this paper, we develop CipherGPT, the first framework for secure two-party GPT inference, building upon a series of innovative protocols. First, we propose a secure matrix multiplication that is customized for GPT inference, achieving upto 6.2× speedup and 4.1× bandwidth reduction over SOTA. We also propose a novel protocol for securely computing GELU, surpassing SOTA by 1.8× in runtime, 2.5× in communication and 7.4× in precision. Furthermore, we come up with the first protocol for secure top-k sampling. We provide a full-fledged implementation and comprehensive benchmark for CipherGPT. In particular, we measure the runtime and communication for each individual operation, along with their corresponding proportions. We believe this can serve as a reference for future research in this area.