activity
20182026
most citedA Block-Permutation-Based Encryption Scheme with Independent Processing of RGB Components

19 citations · 28 across the 9 of their papers we have counts for

collaborators

12 papers

cs.CR2026

Enhancing Privacy in Federated Learning via Dual Obfuscation of Gradients and Training Images

Yuki Itabashi, Hiroto Sawada, Mare Hirose +2

Federated learning enables collaborative model training while keeping data locally at each client; however, recent studies have shown that training data can be reconstructed from s…

cs.CV2026

CFE-PPAR: Compression-friendly encryption for privacy-preserving action recognition leveraging video transformers

Haiwei Lin, Shoko Imaizumi, Hitoshi Kiya

Privacy-preserving action recognition (PPAR) enables machines to understand human activities in videos without revealing sensitive visual content. Among the various strategies for…

cs.CR2026

FLRSP: Privacy-Preserving Federated Learning Using Randomly Selected Model Parameters

Hiroto Sawada, Shoko Imaizumi, Hitoshi Kiya

In this paper, we propose a method for privacy-preserving federated learning that uses randomly selected model parameters to update global models. High-quality deep neural networks…

cs.CV2026

Privacy-Preserving Semantic Segmentation without Key Management

Mare Hirose, Shoko Imaizumi, Hitoshi Kiya

This paper proposes a novel privacy-preserving semantic segmentation method that can use independent keys for each client and image. In the proposed method, the model creator and e…

cs.CR2024

On the Security of Bitstream-level JPEG Encryption with Restart Markers

Mare Hirose, Shoko Imaizumi, Hitoshi Kiya

This paper aims to evaluate the security of a bitstream-level JPEG encryption method using restart (RST) markers, where encrypted image can keep the JPEG file format with the same…

cs.CR2024

Enhancing Security Using Random Binary Weights in Privacy-Preserving Federated Learning

Hiroto Sawada, Shoko Imaizumi, Hitoshi Kiya

In this paper, we propose a novel method for enhancing security in privacy-preserving federated learning using the Vision Transformer. In federated learning, learning is performed…

cs.CV2022

An Overview of Compressible and Learnable Image Transformation with Secret Key and Its Applications

Hitoshi Kiya, AprilPyone MaungMaung, Yuma Kinoshita +2

This article presents an overview of image transformation with a secret key and its applications. Image transformation with a secret key enables us not only to protect visual infor…

cs.MM2021

Application of Reversible Data Hiding for Printing with Special Color Inks to Preserve Compatibility with Normal Printing

Kotoko Hiraoka, Kensuke Fukumoto, Takashi Yamazoe +4

We propose an efficient framework with compatibility between normal printing and printing with special color inks in this paper. Special color inks can be used for printing to repr…

cs.MM2021

Reversible Data Hiding Associated with Digital Halftoning That Allows Printing with Special Color Ink by Using Single Color Layer

Minagi Ueda, Shoko Imaizumi

We propose an efficient framework of reversible data hiding to preserve compatibility between normal printing and printing with a special color ink by using a single common image.…

cs.CR2020★ 9 cited

A Reversible Data Hiding Method in Compressible Encrypted Images

Shoko Imaizumi, Yusuke Izawa, Ryoichi Hirasawa +1

We propose a reversible data hiding (RDH) method in compressible encrypted images called the encryption-then-compression (EtC) images. The proposed method allows us to not only emb…

cs.MM2020★ 19 cited

A Block-Permutation-Based Encryption Scheme with Independent Processing of RGB Components

Shoko Imaizumi, Hitoshi Kiya

This paper proposes a block-permutation-based encryption (BPBE) scheme for the encryption-then-compression (ETC) system that enhances the color scrambling. A BPBE image can be obta…

cs.CR2018

Grayscale-based Block Scrambling Image Encryption for Social Networking Services

Warit Sirichotedumrong, Tatsuya Chuman, Shoko Imaizumi +1

This paper proposes a new block scrambling encryption scheme that enhances the security of encryption-then-compression (EtC) systems for JPEG images, which are used, for example, t…