Jaguar: Fast Private CNN Inference with Power-of-Two Homomorphic Arithmetic

Computer Science > Cryptography and Security [Submitted on 10 Jun 2026] Jaguar: Fast Private CNN Inference with Power-of-Two Homomorphic Arithmetic Yewon Jeong, Nayoung Jung, Hyeri Roh, Woo-Seok Choi Hybrid HE/2PC private CNN inference remains bottlenecked by prime-modulus homomorphic arithmetic in convolution and by a precision flow that runs ReLU at doubled bitwidth before invoking a separate truncation protocol. We present Jaguar, a system built on a single design choice--a power-of-two ciphertext ring--that addresses both. The choice enables SPA-Conv, a coefficient-domain convolution kernel that replaces NTT-centric polynomial multiplication with scalar-polynomial accumulation, and an exact ciphertext-side truncation by local right shifts that lets ReLU run directly at the target fixed-point precision and eliminates the post-ReLU truncation protocol. Where NTT remains genuinely useful--at the client, for the single polynomial multiplication during decryption--we recover it through an auxiliary NTT prime, preserving the power-of-two protocol substrate while keeping decryption O(N log N). On ImageNet-scale ResNet-18, ResNet-50, and MobileNetV2 with AVX disabled, Jaguar achieves 2.07-3.72x lower end-to-end latency than Cheetah and 2.16-3.36x lower than Rhombus, with 1.16-1.76x lower communication than Cheetah. Comments: 29 pages, 8 figures, including appendix Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2606.11827 [cs.CR]   (or arXiv:2606.11827v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2606.11827 Focus to learn more Submission history From: Yewon Jeong [view email] [v1] Wed, 10 Jun 2026 09:04:46 UTC (3,083 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-06 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)