arXiv subjects

Zhengpeng Zhao

Publications and source records attributed to Zhengpeng Zhao.

4 recordsLinked to original sources

arXiv2026

A High Performance and Efficient Post-Quantum Crypto-Processor for FrodoKEM

FrodoKEM is a lattice-based post-quantum key encapsulation mechanism (KEM). It has been considered for standardization by the International Organization for Standardization (ISO) due to its robust security profile. However, its hardware implementation exhibits a weakness of high latency and heavy resource burden, hindering its practical application. Moreover, diverse usage scenarios call for comprehensive functionality. To address these challenges, this paper presents a high-performance and efficient crypto-processor for FrodoKEM. A multiple-instruction overlapped execution scheme is introduced to enable efficient multi-module scheduling and minimize operational latency. Furthermore, a high-speed, reconfigurable parallel multiplier array is integrated to handle intensive matrix computations under diverse computation patterns, significantly enhancing hardware efficiency. In addition, a compact memory scheduling strategy shortens the lifespan of intermediate matrices, thereby reducing overall storage requirements. The proposed design provides full support for all FrodoKEM security levels and protocol phases. It consumes 13467 LUTs, 6042 FFs, and 14 BRAMs on an Artix-7 FPGA and achieves the fastest reported execution time. Compared with state-of-the-art hardware implementations, our design improves the area-time product (ATP) by 1.75-2.00 times.

cs.CR↗

arXiv2025

RORPCap: Retrieval-based Objects and Relations Prompt for Image Captioning

Image captioning aims to generate natural language descriptions for input images in an open-form manner. To accurately generate descriptions related to the image, a critical step in image captioning is to identify objects and understand their relations within the image. Modern approaches typically capitalize on object detectors or combine detectors with Graph Convolutional Network (GCN). However, these models suffer from redundant detection information, difficulty in GCN construction, and high training costs. To address these issues, a Retrieval-based Objects and Relations Prompt for Image Captioning (RORPCap) is proposed, inspired by the fact that image-text retrieval can provide rich semantic information for input images. RORPCap employs an Objects and relations Extraction Model to extract object and relation words from the image. These words are then incorporate into predefined prompt templates and encoded as prompt embeddings. Next, a Mamba-based mapping network is designed to quickly map image embeddings extracted by CLIP to visual-text embeddings. Finally, the resulting prompt embeddings and visual-text embeddings are concatenated to form textual-enriched feature embeddings, which are fed into a GPT-2 model for caption generation. Extensive experiments conducted on the widely used MS-COCO dataset show that the RORPCap requires only 2.6 hours under cross-entropy loss training, achieving 120.5% CIDEr score and 22.0% SPICE score on the "Karpathy" test split. RORPCap achieves comparable performance metrics to detector-based and GCN-based models with the shortest training time and demonstrates its potential as an alternative for image captioning.

cs.CV↗

arXiv2025

NVR: Vector Runahead on NPUs for Sparse Memory Access

Deep Neural Networks are increasingly leveraging sparsity to reduce the scaling up of model parameter size. However, reducing wall-clock time through sparsity and pruning remains challenging due to irregular memory access patterns, leading to frequent cache misses. In this paper, we present NPU Vector Runahead (NVR), a prefetching mechanism tailored for NPUs to address cache miss problems in sparse DNN workloads. Rather than optimising memory patterns with high overhead and poor portability, NVR adapts runahead execution to the unique architecture of NPUs. NVR provides a general micro-architectural solution for sparse DNN workloads without requiring compiler or algorithmic support, operating as a decoupled, speculative, lightweight hardware sub-thread alongside the NPU, with minimal hardware overhead (under 5%). NVR achieves an average 90% reduction in cache misses compared to SOTA prefetching in general-purpose processors, delivering 4x average speedup on sparse workloads versus NPUs without prefetching. Moreover, we investigate the advantages of incorporating a small cache (16KB) into the NPU combined with NVR. Our evaluation shows that expanding this modest cache delivers 5x higher performance benefits than increasing the L2 cache size by the same amount.

cs.AR↗

arXiv2025

Pushing the Limits of BFP on Narrow Precision LLM Inference

The substantial computational and memory demands of Large Language Models (LLMs) hinder their deployment. Block Floating Point (BFP) has proven effective in accelerating linear operations, a cornerstone of LLM workloads. However, as sequence lengths grow, nonlinear operations, such as Attention, increasingly become performance bottlenecks due to their quadratic computational complexity. These nonlinear operations are predominantly executed using inefficient floating-point formats, which renders the system challenging to optimize software efficiency and hardware overhead. In this paper, we delve into the limitations and potential of applying BFP to nonlinear operations. Given our findings, we introduce a hardware-software co-design framework (DB-Attn), including: (i) DBFP, an advanced BFP version, overcomes nonlinear operation challenges with a pivot-focus strategy for diverse data and an adaptive grouping strategy for flexible exponent sharing. (ii) DH-LUT, a novel lookup table algorithm dedicated to accelerating nonlinear operations with DBFP format. (iii) An RTL-level DBFP-based engine is implemented to support DB-Attn, applicable to FPGA and ASIC. Results show that DB-Attn provides significant performance improvements with negligible accuracy loss, achieving 74% GPU speedup on Softmax of LLaMA and 10x low overhead performance improvement over SOTA designs.

cs.AR↗