{"ID":2875758,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2509.01178","arxiv_id":"2509.01178","title":"Efficient and High-Accuracy Secure Two-Party Protocols for a Class of Functions with Real-number Inputs","abstract":"In two-party secret sharing scheme, values are typically encoded as unsigned integers $\\mathsf{uint}(x)$, whereas real-world applications often require computations on signed real numbers $\\mathsf{Real}(x)$. To enable secure evaluation of practical functions, it is essential to computing $\\mathsf{Real}(x)$ from shared inputs, as protocols take shares as input. At USENIX'25, Guo et al. proposed an efficient method for computing signed integer values $\\mathsf{int}(x)$ from shares, which can be extended to compute $\\mathsf{Real}(x)$. However, their approach imposes a restrictive input constraint $|x| \u003c \\frac{L}{3}$ for $x \\in \\mathbb{Z}_L$, limiting its applicability in real-world scenarios. In this work, we significantly relax this constraint to $|x| \u003c B$ for any $B \\leq \\frac{L}{2}$, where $B = \\frac{L}{2}$ corresponding to the natural representable range in $x \\in \\mathbb{Z}_L$. This relaxes the restrictions and enables the computation of $\\mathsf{Real}(x)$ with loose or no input constraints. Building upon this foundation, we present a generalized framework for designing secure protocols for a broad class of functions, including integer division ($\\lfloor \\frac{x}{d} \\rfloor$), trigonometric ($\\sin(x)$) and exponential ($e^{-x}$) functions. Our experimental evaluation demonstrates that the proposed protocols achieve both high efficiency and high accuracy. Notably, our protocol for evaluating $e^{-x}$ reduces communication costs to approximately 31% of those in SirNN (S\u0026P 21) and Bolt (S\u0026P 24), with runtime speedups of up to $5.53 \\times$ and $3.09 \\times$, respectively. In terms of accuracy, our protocol achieves a maximum ULP error of $1.435$, compared to $2.64$ for SirNN and $8.681$ for Bolt.","short_abstract":"In two-party secret sharing scheme, values are typically encoded as unsigned integers $\\mathsf{uint}(x)$, whereas real-world applications often require computations on signed real numbers $\\mathsf{Real}(x)$. To enable secure evaluation of practical functions, it is essential to computing $\\mathsf{Real}(x)$ from shared...","url_abs":"https://arxiv.org/abs/2509.01178","url_pdf":"https://arxiv.org/pdf/2509.01178v1","authors":"[\"Hao Guo\",\"Zhaoqian Liu\",\"Liqiang Peng\",\"Shuaishuai Li\",\"Ximing Fu\",\"Weiran Liu\",\"Lin Qu\"]","published":"2025-09-01T06:56:29Z","proceeding":"cs.CR","tasks":"[\"cs.CR\"]","methods":"[]","has_code":false}