Publications

Journal Articles

• DNN Data Hiding for Transformer Encoder in ViT Models

  Shuntaro Fukuoka, Shoko Imaizumi, and Minoru Kuribayashi,
  “DNN Data Hiding for Transformer Encoder in ViT Models,”
  Bull. Soc. Photogr. Imag. Japan, vol.34, no.2, pp.20-30, November 2024.

• Privacy-Preserving ConvMixer Without Any Accuracy Degradation Using Compressible Encrypted Images

  Haiwei Lin, Shoko Imaizumi, and Hitoshi Kiya,
  “Privacy-Preserving ConvMixer Without Any Accuracy Degradation Using Compressible Encrypted Images,”
  Information, vol.15, no.723, November 2024.

• Encryption Method for JPEG Bitstreams for Partially Disclosing Visual Information

  Mare Hirose, Shoko Imaizumi, and Hitoshi Kiya,
  “Encryption Method for JPEG Bitstreams for Partially Disclosing Visual Information,”
  Electronics, vol.13, no.2016, May 2024.

• An Extended Method for Reversible Color Tone Control Using Data Hiding

  Daichi Nakaya and Shoko Imaizumi,
  “An Extended Method for Reversible Color Tone Control Using Data Hiding,”
  Electronics, vol.13, no.1204, March 2024.

• Security Enhancement for Reversible Data Hiding for Palette-Based Images

  Noa Kikuchi and Shoko Imaizumi,
  “Security Enhancement for Reversible Data Hiding for Palette-Based Images,”
  Bull. Soc. Photogr. Imag. Japan, vol.34, no.1, pp.1-8, March 2024.

• Reversible Data Hiding in Compressible Encrypted Images with Capacity Enhancement

  Ryota Motomura, Shoko Imaizumi, and Hitoshi Kiya,
  “Reversible Data Hiding in Compressible Encrypted Images with Capacity Enhancement,”
  APSIPA Trans. Signal Inf. Process., vol.12, no.1, July 2023.

• Effects of JPEG Compression on Vision Transformer Image Classification for Encryption-then-Compression Images

  Genki Hamano, Shoko Imaizumi, and Hitoshi Kiya,
  “Effects of JPEG Compression on Vision Transformer Image Classification for Encryption-then-Compression Images,”
  Sensors, vol.23, no.3400, March 2023.

• Security Enhancement for Reversible Data Hiding for Palette-Based Images

  Daichi Nakaya and Shoko Imaizumi,
  “Security Enhancement for Reversible Data Hiding for Palette-Based Images,”
  Bull. Soc. Photogr. Imag. Japan, vol.33, no.1, pp.1-6, March 2023.
  Best Paper Award of SPIJ Prize

• Reversible Image Processing for Color Images with Flexible Control

  Yuki Sugimoto and Shoko Imaizumi,
  “Reversible Image Processing for Color Images with Flexible Control,”
  Appl. Sci., vol.13, no.2297, February 2023.

• A Reversible Data Hiding Method with Prediction-Error Expansion in Compressible Encrypted Images

  Ryota Motomura, Shoko Imaizumi, and Hitoshi Kiya,
  “A Reversible Data Hiding Method with Prediction-Error Expansion in Compressible Encrypted Images,”
  Appl. Sci., vol.12, no.9418, September 2022.

• Privacy-Preserving Semantic Segmentation Using Vision Transformer

  Hitoshi Kiya, Teru Nagamori, Shoko Imaizumi, and Sayaka Shiota,
  “Privacy-Preserving Semantic Segmentation Using Vision Transformer,”
  J. Imaging, vol.8, no.233, August 2022.

• High-Capacity Reversible Data Hiding in Encrypted Images with Flexible Restoration

  Eichi Arai and Shoko Imaizumi,
  “High-Capacity Reversible Data Hiding in Encrypted Images with Flexible Restoration,”
  J. Imaging, vol.8, no.176, June 2022.

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

  Hitoshi Kiya, April Pyone Maung Maung, Yuma Kinoshita, Shoko Imaizumi, and Sayaka Shiota,
  “An Overview of Compressible and Learnable Image Transformation with Secret Key and Its Applications,”
  APSIPA Trans. Signal Inf. Process., vol.11, no.1, May 2022.

• An Extension of Reversible Image Enhancement Processing for Saturation and Brightness Contrast

  Yuki Sugimoto and Shoko Imaizumi,
  “An Extension of Reversible Image Enhancement Processing for Saturation and Brightness Contrast,”
  J. Imaging, vol.8, no.27, January 2022.

• A Reversible Data Hiding Method in Encrypted Images for Controlling Trade-Off between Hiding Capacity and Compression Efficiency

  Ryota Motomura, Shoko Imaizumi, and Hitoshi Kiya,
  “A Reversible Data Hiding Method in Encrypted Images for Controlling Trade-Off between Hiding Capacity and Compression Efficiency,”
  J. Imaging, vol.7, no.268, December 2021.

• An Extended PEE-HS Based Method for Reversible Data Hiding of Depth Images

  Minagi Ueda, Ayaka Matsuda, Ikuma Yasukawa and Shoko Imaizumi,
  “An Extended PEE-HS Based Method for Reversible Data Hiding of Depth Images,”
  IEEJ Trans. Electr. Inf. & Syst., vol.141, no.9, pp.1032-1038, September 2021. (in Japanese)

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

  Minagi Ueda and Shoko Imaizumi,
  “Reversible Data Hiding Associated with Digital Halftoning That Allows Printing with Special Color Ink by Using Single Color Layer,”
  IEEJ Trans. Electr. Inf. & Syst., vol.141, no.2, pp.163-164, February 2021.

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

  Kotoko Hiraoka, Kensuke Fukumoto, Takashi Yamazoe, Norimichi Tsumura, Satoshi Kaneko, Wataru Arai, and Shoko Imaizumi,
  “Application of Reversible Data Hiding for Printing with Special Color Inks to Preserve Compatibility with Normal Printing,”
  IEEJ Trans. Electr. Inf. & Syst., vol.141, no.2, pp.155-162, February 2021.

• A Reversible Data Hiding Method in Compressible Encrypted Images

  Shoko Imaizumi, Yusuke Izawa, Ryoichi Hirasawa, and Hitoshi Kiya,
  “A Reversible Data Hiding Method in Compressible Encrypted Images,”
  IEICE Trans. Fundamentals, vol.E103-A, no.12, pp.1579-1588, December 2020.

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

  Shoko Imaizumi and Hitoshi Kiya,
  “A Block-Permutation-Based Encryption Scheme with Independent Processing of RGB Components,”
  IEICE Trans. Inf. & Syst., vol.E101-D, no.12, pp.3150-3157, December 2018.

• Integrated Model of Image Protection Techniques

  Anu Aryal, Shoko Imaizumi, Takahiko Horiuchi, and Hitoshi Kiya,
  “Integrated Model of Image Protection Techniques,”
  J. Imaging, vol.4, no.1, January 2018.

• Block-Permutation-Based Encryption Scheme with Enhanced Color Scrambling

  Shoko Imaizumi, Takeshi Ogasawara, and Hitoshi Kiya,
  “Block-Permutation-Based Encryption Scheme with Enhanced Color Scrambling,”
  Lect. Notes Comput. Sci., P. Sharma, F. Bianchi (Eds.), Springer-Verlag, vol.10269, pp.562-573, May 2017.

• An Encryption-then-Compression System for Lossless Image Compression Standards

  Kenta Kurihara, Shoko Imaizumi, Sayaka Shiota, and Hitoshi Kiya,
  “An Encryption-then-Compression System for Lossless Image Compression Standards,”
  IEICE Trans. Inf. & Syst., vol.E100-D, no.1, pp.52-56, January 2017.

• Hierarchical Scrambling Method for Palette-Based Image Using Bitwise Operation

  Anu Aryal, Shoko Imaizumi, and Takahiko Horiuchi,
  “Hierarchical Scrambling Method for Palette-Based Image Using Bitwise Operation,”
  Bull. Soc. Photogr. Imag. Japan, vol.26, no.1, pp.1-9, June 2016.

• A Robust Identification Scheme for JPEG XR Images with Various Compression Ratios

  Hiroyuki Kobayashi, Shoko Imaizumi, and Hitoshi Kiya,
  “A Robust Identification Scheme for JPEG XR Images with Various Compression Ratios,”
  Lect. Notes Comput. Sci., T. Bräunl, B. McCane, M. Rivera, and X. Yu (Eds.), Springer-Verlag, vol.9431, pp.38-50, February 2016.

• Scalable Tamper Detection and Localization Scheme for JPEG2000 Codestreams

  Takeshi Ogasawara, Shoko Imaizumi, and Naokazu Aoki,
  “Scalable Tamper Detection and Localization Scheme for JPEG2000 Codestreams,”
  Lect. Notes Comput. Sci., Y. -S. Ho, J. Sang, Y. M. Ro, J. Kim, and F. Wu (Eds.), Springer-Verlag, vol.9315, pp.340-349, December 2015.

• An Encryption-then-Compression System for JPEG / Motion JPEG Standard

  Kenta Kurihara, Masanori Kikuchi, Shoko Imaizumi, Sayaka Shiota, and Hitoshi Kiya,
  “An Encryption-then-Compression System for JPEG / Motion JPEG Standard,”
  IEICE Trans. Fundamentals, vol.E98-A, no.11, pp.2238-2245, November 2015.

• Improvement of Multibit Information Embedding Algorithm for Palette-Based Images

  Anu Aryal, Kazuma Motegi, Shoko Imaizumi, and Naokazu Aoki,
  “Improvement of Multibit Information Embedding Algorithm for Palette-Based Images,”
  Lect. Notes Comput. Sci., J. Lopez and C. J. Mitchell (Eds.), Springer-Verlag, vol.9290, pp.511-523, August 2015.

• Palette-Based Image Steganography for High-Capacity Embedding

  Shoko Imaizumi and Kei Ozawa,
  “Palette-Based Image Steganography for High-Capacity Embedding,”
  Bull. Soc. Photogr. Imag. Japan, vol.25, no.1, pp.7-11, June 2015.

• Hierarchical Image Authentication Based on Reversible Data Hiding

  Shoko Imaizumi and Kanichi Taniguchi,
  “Hierarchical Image Authentication Based on Reversible Data Hiding,”
  Bull. Soc. Photogr. Imag. Japan, vol.24, no.1, pp.1-5, June 2014.
  Best Paper Award of SPIJ Prize

• Multibit Embedding Algorithm for Steganography of Palette-Based Images

  Shoko Imaizumi and Kei Ozawa,
  “Multibit Embedding Algorithm for Steganography of Palette-Based Images,”
  Lect. Notes Comput. Sci., R. Klette, M. Rivera, S. Satoh (Eds.), Springer-Verlag, vol.8333, pp.99-110, January 2014.

• Multiple Level Access Control Method for Hierarchical Multimedia Content Using Low-complexity Key Generating Schemes

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “Multiple Level Access Control Method for Hierarchical Multimedia Content Using Low-complexity Key Generating Schemes,”
  ITE Journal, vol.66, no.2, pp.69-73, February 2012. (in Japanese)

• A Key Derivation Scheme for Hierarchical Access Control to JPEG 2000 Coded Images

  Shoko Imaizumi, Masaaki Fujiyoshi, Hitoshi Kiya, Naokazu Aoki, and Hiroyuki Kobayashi,
  “A Key Derivation Scheme for Hierarchical Access Control to JPEG 2000 Coded Images,”
  Lect. Notes Comput. Sci., Y. -S. Ho (Ed.), Springer-Verlag, vol.7088, pp.180-191, January 2012.

• A Key Generating Method Using Recursive Hash Chains and Its Applications for Multi-Dimensionally Hierarchical Access Control

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “A Key Generating Method Using Recursive Hash Chains and Its Applications for Multi-Dimensionally Hierarchical Access Control,”
  ITE Journal, vol.65, no.2, pp.193-202, February 2011. (in Japanese)
  Best Paper Award of ITE Niwa-Takayanagi Prize

• An Efficient Access Control Method Based on One-Way Hash Functions for Digital Videos

  Shoko Imaizumi, Yoshito Abe, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “An Efficient Access Control Method Based on One-Way Hash Functions for Digital Videos,”
  ITE Journal, vol.64, no.11, pp.1621-1627, November 2010. (in Japanese)

• An efficient access control method for composite multimedia content

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “An efficient access control method for composite multimedia content,”
  IEICE Electronics Express, vol.7, no.20, pp.1534-1538, October 2010.

• Encryption of Composite Multimedia Contents for Access Control

  Masaaki Fujiyoshi, Shoko Imaizumi, and Hitoshi Kiya,
  “Encryption of Composite Multimedia Contents for Access Control,”
  IEICE Trans. Fundamentals, vol.E90-A, no.3, pp.590-596, March 2007.

• Partial-Scrambling of JPEG2000 Images without Generating Marker Codes

  Hitoshi Kiya, Shoko Imaizumi, and Osamu Watanabe,
  “Partial-Scrambling of JPEG2000 Images without Generating Marker Codes,”
  IEICE Trans., vol.J86-D-II, no.11, pp.1628-1636, November 2003. (in Japanese)

Book Chapter

• A Novel Access Control Scheme for Multimedia Content with Modified Hash Chain

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “A Novel Access Control Scheme for Multimedia Content with Modified Hash Chain,”
  inMultimedia – A Multidisciplinary Approach to Complex Issues(edited by Ioannis Karydis), pp.85-98, Intech, March 2012.

International Conference Papers

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

  Mare Hirose, Shoko Imaizumi, and Hitoshi Kiya,
  “On the Security of Bitstream-level JPEG Encryption with Restart Markers,”
  inProc. of APSIPA Annual Summit and Conference, Macau, China, 5th November, 2024.

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

  Hiroto Sawada, Shoko Imaizumi, and Hitoshi Kiya,
  “Enhancing Security Using Random Binary Weights in Privacy-Preserving Federated Learning,”
  inProc. of APSIPA Annual Summit and Conference, Macau, China, 5th November, 2024.

• Perceptual Collation Method for Colour Halftone Images Based on Visual Saliency

  Taiga Baba, Midori Tanaka, Shoko Imaizumi, and Takahiko Horiuchi,
  “Perceptual Collation Method for Colour Halftone Images Based on Visual Saliency,”
  inProc. of Congress of the International Colour Association, 6 pages, Chiang Rai, Thailand, 30th November, 2023.

• A Reversible Image Processing Method for Color Tone Control Using Data Hiding

  Daichi Nakaya and Shoko Imaizumi,
  “A Reversible Image Processing Method for Color Tone Control Using Data Hiding,”
  inProc. of APSIPA Annual Summit and Conference, pp.599-504, Taipei, Taiwan, R.O.C., 1st November, 2023.

• Effects of Data Hiding on Vision Transformer Classification for Encryption-Then-Compression Images

  Kosuke Abe, Shoko Imaizumi, and Hitoshi Kiya,
  “Effects of Data Hiding on Vision Transformer Classification for Encryption-Then-Compression Images,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.798-800, Nara, Japan, 12th October, 2023.

• Protection of Residual Layer for JPEG XT Images Using Reversible Data Hiding

  Noa Kikuchi and Shoko Imaizumi,
  “Protection of Residual Layer for JPEG XT Images Using Reversible Data Hiding,”
  inProc. of Satellite International Conference on Advanced Imaging, pp.27-28, Chiba, Japan, 29th July, 2023.

• A Reversible Image Processing Method with Selectable Functions

  Yuki Sugimoto and Shoko Imaizumi,
  “A Reversible Image Processing Method with Selectable Functions,”
  inProc. of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, 4 pages, Penang, Malaysia (online), 24th November, 2022.

• Image Classification Using Vision Transformer for EtC Images

  Genki Hamano, Shoko Imaizumi, and Hitoshi Kiya,
  “Image Classification Using Vision Transformer for EtC Images,”
  inProc. of APSIPA Annual Summit and Conference, pp.1506-1513, Chiang Mai, Thailand (online), 10th November, 2022.

• A reversible Data Hiding Method in Compressible Encrypted Domain for OpenEXR Images

  Noa Kikuchi and Shoko Imaizumi,
  “A reversible Data Hiding Method in Compressible Encrypted Domain for OpenEXR Images,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.38-40, Osaka, Japan, 18th October, 2022.

• An Extension of High-Capacity Reversible Data Hiding in Encrypted Images with Bit-Plane Partition

  Eichi Arai and Shoko Imaizumi,
  “An Extension of High-Capacity Reversible Data Hiding in Encrypted Images with Bit-Plane Partition,”
  inProc. of IEEE International Conference on Consumer Electronics – Taiwan, pp.459-460, Taipei, Taiwan, R.O.C. (online), 8th July, 2022.

• An Extended RDH Method for HDR Images Using Edge Estimation

  Minagi Ueda, Shoko Imaizumi, and KokSheik Wong,
  “An Extended RDH Method for HDR Images Using Edge Estimation,”
  inProc. of APSIPA Annual Summit and Conference, pp.1821-1827, Tokyo, Japan, 17th December, 2021.

• A Flexible Reversible Data Hiding Method in Compressive Encrypted Images

  Ryota Motomura, Shoko Imaizumi, and Hitoshi Kiya,
  “A Flexible Reversible Data Hiding Method in Compressive Encrypted Images,”
  inProc. of APSIPA Annual Summit and Conference, pp.1794-1799, Tokyo, Japan, 16th December, 2021.

• An Efficient Data Hiding Method Using Correlation Coefficients among Index Colors for Palette-Based Images

  Eichi Arai and Shoko Imaizumi,
  “An Efficient Data Hiding Method Using Correlation Coefficients among Index Colors for Palette-Based Images,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.407-410, Kyoto, Japan, 13th October, 2021.

• A Perception-Based Collation Method Using CNN for Color Halftone Images

  Yuto Matsuoka, Shoko Imaizumi, and Takahiko Horiuchi,
  “A Perception-Based Collation Method Using CNN for Color Halftone Images,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.91-94, Kyoto, Japan, 12th October, 2021.

• A Lossless Image Processing Method with Contrast and Saturation Enhancement

  Yuki Sugimoto and Shoko Imaizumi,
  “A Lossless Image Processing Method with Contrast and Saturation Enhancement,”
  inProc. of IEEE International Workshop on Multimedia Signal Processing, no.156, Tampere, Finland (online), 7th October, 2021.

• An MSB Prediction-Based Method with Marker Bits for Reversible Data Hiding in Encrypted Images

  Ryoichi Hirasawa, Shoko Imaizumi, and Hitoshi Kiya,
  “An MSB Prediction-Based Method with Marker Bits for Reversible Data Hiding in Encrypted Images,”
  inProc. of IEEE Global Conference on Life Sciences and Technologies, pp.48-50, Nara, Japan, 9th March, 2021.

• Flexible Data Hiding and Extraction in EtC Images

  Ryoichi Hirasawa, Shoko Imaizumi, and Hitoshi Kiya,
  “Flexible Data Hiding and Extraction in EtC Images,”
  inProc. of APSIPA Annual Summit and Conference, no.B-2-2.2, pp.1347-1351, Auckland, New Zealand (online), 9th December, 2020.

• Perceptual Collation Method for Multi-Level Color Halftone Image Based on Visual Characteristics

  Ren Nakamura, Takahiko Horiuchi, Midori Tanaka, Shoko Imaizumi, and Tomoyuki Takanashi,
  “Perceptual Collation Method for Multi-Level Color Halftone Image Based on Visual Characteristics,”
  inProc. of Colour and Visual Computing Symposium, CEUR Workshop Proceedings 2668, 13 pages, Gjøvik, Norway (online), 16th September, 2020.

• A Reversible Data Hiding Scheme for Printing with Special Color Inks Using Digital Halftoning

  Minagi Ueda and Shoko Imaizumi,
  “A Reversible Data Hiding Scheme for Printing with Special Color Inks Using Digital Halftoning,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.1159-1162, Osaka, Japan, 18th October, 2019.

• A Reversible Data Hiding Scheme Using Difference Values Based on Similarity Between Adjacent Pixels

  Hinata Seguchi and Shoko Imaizumi,
  “A Reversible Data Hiding Scheme Using Difference Values Based on Similarity Between Adjacent Pixels,”
  inProc. of IEEE Global Conference on Consumer Electronics, pp.1131-1134, Osaka, Japan, 18th October, 2019.

• A Block-Permutation-Based Image Encryption Allowing Hierarchical Decryption

  Yusuke Izawa, Shoko Imaizumi, and Hitoshi Kiya,
  “A Block-Permutation-Based Image Encryption Allowing Hierarchical Decryption,”
  inProc. of APSIPA Annual Summit and Conference, no.TH-A1-4.1, Honolulu, USA, 15th November, 2018.

• Grayscale-based Block Scrambling Image Encryption for Social Networking Services

  Warit Sirichotedumrong, Tatsuya Chuman, Shoko Imaizumi, and Hitoshi Kiya,
  “Grayscale-based Block Scrambling Image Encryption for Social Networking Services,”
  inProc. IEEE International Conference on Multimedia and Expo, San Diego, USA, 23rd July, 2018.

• Encryption System for Digital Archiving of Cultural Properties

  Hiroki Ujiie, Shoko Imaizumi, Takeshi Ogasawara, Kazuma Motegi, Seiji Shirono, and Mai Sarai,
  “Encryption System for Digital Archiving of Cultural Properties,”
  inProc. of International Workshop on Advanced Image Technology, no.131(PS1-18), Chiang Mai, Thailand, 9th January, 2018.

• Integrated Algorithm for Block-Permutation-Based Encryption with Reversible Data Hiding

  Anu Aryal, Shoko Imaizumi, Takahiko Horiuchi, and Hitoshi Kiya,
  “Integrated Algorithm for Block-Permutation-Based Encryption with Reversible Data Hiding,”
  inProc. of APSIPA Annual Summit and Conference, no.WA-08.2, Kuala Lumpur, Malaysia, 13th December, 2017.

• Block-Permutation-Based Encryption Scheme with Enhanced Color Scrambling

  Shoko Imaizumi, Takeshi Ogasawara, and Hitoshi Kiya,
  “Block-Permutation-Based Encryption Scheme with Enhanced Color Scrambling,”
  inProc. of Scandinavian Conference on Image Analysis, LNCS 10269, pp.562-573, Tromso, Norway, 13th June, 2017.

• Image Authentication Scheme with Localization Using YIQ Color Space

  Kazuma Motegi and Shoko Imaizumi,
  “Image Authentication Scheme with Localization Using YIQ Color Space,”
  inProc. of International Workshop on Advanced Image Technology, no.2B-6, Penang, Malaysia, 9th January, 2017.

• A Robust Identification Scheme for JPEG XR Images with Various Compression Ratios

  Hiroyuki Kobayashi, Shoko Imaizumi, and Hitoshi Kiya,
  “A Robust Identification Scheme for JPEG XR Images with Various Compression Ratios,”
  inProc. of Pacific-Rim Symposium on Image and Video Technology, LNCS 9431, pp.38-50, Auckland, New Zealand, 25th November, 2015.

• Scalable Tamper Detection and Localization Scheme for JPEG2000 Codestreams

  Takeshi Ogasawara, Shoko Imaizumi, and Naokazu Aoki,
  “Scalable Tamper Detection and Localization Scheme for JPEG2000 Codestreams,”
  inProc. of Pacific-Rim Conference on Multimedia, LNCS 9315, pp.340-349, Gwangju, Korea, 17th September, 2015.

• Improvement of Multibit Information Embedding Algorithm for Palette-Based Images

  Anu Aryal, Kazuma Motegi, Shoko Imaizumi, and Naokazu Aoki,
  “Improvement of Multibit Information Embedding Algorithm for Palette-Based Images,”
  inProc. of Information Security Conference, LNCS 9290, pp.511-523, Trondheim, Norway, 11th September, 2015.

• Hierarchical Scrambling for Palette-Based Images Using Transposition Cipher

  Anu Aryal, Shoko Imaizumi, and Naokazu Aoki,
  “Hierarchical Scrambling for Palette-Based Images Using Transposition Cipher,”
  inProc. of International Conference on Advanced Imaging, no.T109-01, pp.701-704, Tokyo, Japan, 19th June, 2015.

• Flexible Partial Encryption for Palette-Based Images

  Shoko Imaizumi and Yuto Tobe,
  “Flexible Partial Encryption for Palette-Based Images,”
  inProc. of International Workshop on Advanced Image Technology, no.160, Tainan, Taiwan, R.O.C., 12th January, 2015.

• Hierarchical Scrambling Scheme for Palette-Based Images

  Anu Aryal, Shoko Imaizumi, and Naokazu Aoki,
  “Hierarchical Scrambling Scheme for Palette-Based Images,”
  inProc. of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, no.74, pp.65-70, Kuching, Malaysia, 2nd December, 2014.

• Multibit Embedding Algorithm for Steganography of Palette-Based Images

  Shoko Imaizumi and Kei Ozawa,
  “Multibit Embedding Algorithm for Steganography of Palette-Based Images,”
  inProc. of Pacific-Rim Symposium on Image and Video Technology, LNCS 8333, pp.99-110, Guanajuato, Mexico, 30th October, 2013.

• A Collusion-Free Key Assignment Scheme for Hierarchical Access Control Using Recursive Hash Chains

  Shoko Imaizumi,
  “A Collusion-Free Key Assignment Scheme for Hierarchical Access Control Using Recursive Hash Chains,”
  inProc. of IEEE International Symposium on Circuits and Systems, no.A3L-A-4, pp.445-448, Beijing, China, 20th May, 2013.

• A High-Capacity Data Embedding Scheme for Palette-Based Images with High Image Quality

  Kei Ozawa, Shoko Imaizumi, Naokazu Aoki, and Hiroyuki Kobayashi,
  “A High-Capacity Data Embedding Scheme for Palette-Based Images with High Image Quality,”
  inProc. of International Workshop on Advanced Image Technology, no.SPS-27, p.806, Nagoya, Japan, 8th January, 2013.

• Multi-dimensional Key Assignment for Hierarchical Media Access Control with Collusion Resilience

  Shoko Imaizumi, Naokazu Aoki, Hiroyuki Kobayashi, and Hitoshi Kiya,
  “Multi-dimensional Key Assignment for Hierarchical Media Access Control with Collusion Resilience,”
  inProc. of IARIA International Conference on Systems and Networks Communications, pp.77-82, Lisbon, Portugal, 20th November, 2012.

• A Visible Data Hiding Scheme for Printed Color Images

  Yuto Tobe, Shoko Imaizumi, Naokazu Aoki, and Hiroyuki Kobayashi,
  “A Visible Data Hiding Scheme for Printed Color Images,”
  inProc. of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, no.E4.4, pp.653-657, New Taipei City, Taiwan, R.O.C., 6th November, 2012.

• Hierarchical Key Assignment Scheme for Multimedia Access Control with Modified Hash Chain

  Shoko Imaizumi, Naokazu Aoki, Hiroyuki Kobayashi, and Hitoshi Kiya,
  “Hierarchical Key Assignment Scheme for Multimedia Access Control with Modified Hash Chain,”
  inProc. of IEEE International Conference on Intelligent Information Hiding and Multimedia Signal Processing, no.CM-2.1, pp.293-296, Piraeus, Greece, 20th July, 2012.

• Key Derivation Scheme for Hierarchical Access Control to Multimedia Content

  Shoko Imaizumi, Masaaki Fujiyoshi, Hitoshi Kiya, Naokazu Aoki, and Hiroyuki Kobayashi,
  “Key Derivation Scheme for Hierarchical Access Control to Multimedia Content,”
  inProc. of International Workshop on Advanced Image Technology, no.F-4, pp.246-251, Ho Chi Minh City, Vietnam, 10th January, 2012.

• A Key Derivation Scheme for Hierarchical Access Control to JPEG 2000 Coded Images

  Shoko Imaizumi, Masaaki Fujiyoshi, Hitoshi Kiya, Naokazu Aoki, and Hiroyuki Kobayashi,
  “A Key Derivation Scheme for Hierarchical Access Control to JPEG 2000 Coded Images,”
  inProc. of Pacific-Rim Symposium on Image and Video Technology, Part II, LNCS 7088, pp.180-191, Gwangju, Korea, 22nd November, 2011.

• An Efficient Access Control Scheme for Multimedia Content Using Modified Hash Chain

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “An Efficient Access Control Scheme for Multimedia Content Using Modified Hash Chain,”
  inProc. of IARIA International Conference on Systems and Networks Communications, pp.175-180, Barcelona, Spain, 26th October, 2011.

• Efficient Collusion Attack-Free Access Control for JPEG 2000 Coded Images

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “Efficient Collusion Attack-Free Access Control for JPEG 2000 Coded Images,”
  inProc. of APSIPA Annual Summit and Conference, no.MP-P2-6, pp.270-273, Sapporo, Japan, 5th October, 2009.

• Efficient Collusion Attack-Free Access Control for Multidimensionally Hierarchical Scalability Content

  Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “Efficient Collusion Attack-Free Access Control for Multidimensionally Hierarchical Scalability Content,”
  inProc. of IEEE International Symposium on Circuits and Systems, no.A3L-F-4, pp.505-508, Taipei, Taiwan, R.O.C., 25th May, 2009.

• Hierarchical Encryption Using Short Encryption Keys for Scalable Access Control of JPEG 2000 Coded Images

  Noriaki Hashimoto, Shoko Imaizumi, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “Hierarchical Encryption Using Short Encryption Keys for Scalable Access Control of JPEG 2000 Coded Images,”
  inProc. of IEEE International Conference on Image Processing, no.WP-PG.4, pp.3116-3119, San Diego, CA, the US, 15th October, 2008.

• Collusion Attack-Resilient Hierarchical Encryption of JPEG 2000 Codestreams with Scalable Access Control

  Shoko Imaizumi, Masaaki Fujiyoshi, Yoshito Abe, and Hitoshi Kiya,
  “Collusion Attack-Resilient Hierarchical Encryption of JPEG 2000 Codestreams with Scalable Access Control,”
  inProc. of IEEE International Conference on Image Processing, vol.II, no.MP-L5.3, pp.137-140, San Antonio, TX, the U.S., 17th September, 2007.

• Hierarchical Cipher for Controlling Access to Multimedia Contents

  Masaaki Fujiyoshi, Wataru Saitou, Shoko Imaizumi, and Hitoshi Kiya,
  “Hierarchical Cipher for Controlling Access to Multimedia Contents,”
  inProc. of International Technical Conference on CircuitsSystems, Computers and Communications/, vol.II, no.WAM1-4-4, pp.69-72, Chiang Mai, Thailand, 12th July, 2006.

• Generalized Hierarchical Encryption of JPEG 2000 Codestreams for Access Control

  Shoko Imaizumi, Osamu Watanabe, Masaaki Fujiyoshi, and Hitoshi Kiya,
  “Generalized Hierarchical Encryption of JPEG 2000 Codestreams for Access Control,”
  inProc. of IEEE International Conference on Image Processing, vol.II, no.TuePmPO5.6, pp.1094-1097, Genoa, Italy, 13th September, 2005.

• Partial-Scrambling of Image Encoded Using JPEG2000 without Generating Marker Codes

  Hitoshi Kiya, Shoko Imaizumi, and Osamu Watanabe,
  “Partial-Scrambling of Image Encoded Using JPEG2000 without Generating Marker Codes,”
  inProc. of IEEE International Conference on Image Processing, no.WA-P1.3, pp.III-205-208, Barcelona, Spain, 17th September, 2003.

• Lossless Inter-Frame Video Coding Using Extended JPEG2000

  Shoko Imaizumi, Ayuko Takagi, and Hitoshi Kiya,
  “Lossless Inter-Frame Video Coding Using Extended JPEG2000,”
  inProc. of International Technical Conference on CircuitsSystems, Computers and Communications/, Phuket, Thailand, 1st July, 2002.