△ Research team led by Professor Kim Jong Sung (Department of Information Security and Cryptography)

The DF&C (Digital Forensic & Cryptanalysis) Laboratory, led by Professor Kim Jong-sung of the Department of Information Security, Cryptography, and Cyber Security at Kookmin University (President Jeong Seung Ryul), has demonstrated its international research competitiveness by presenting research findings on cryptographic circuit optimization for the second consecutive year at CHES, a world-renowned cryptography conference.
 
Professor Kim Jong Sung’s research team at Kookmin University (Ph.D. candidate Baek Seung-jun and Professor Kim Jong-sung), in collaboration with Professor Kim Ki-yoon of Pukyong National University, Jeong Yong-jin, a researcher at KU Leuven in Belgium, and Vedad Hadžić, a researcher at Intel Corporation, at the Conference on Cryptographic Hardware and Embedded Systems (hereinafter CHES), held in Antalya, Türkiye, from Sunday, October 11, to Thursday, October 15. The paper was also published in the international journal *IACR Transactions on Cryptographic Hardware and Embedded Systems* (TCHES).
 
CHES is one of the world’s most prestigious academic conferences in the field of cryptographic hardware and embedded systems, held annually since 1999. The paper presented, titled “Bitsliced Segment-Based Search Technique for Low-Depth and Hardware-Efficient S-Box Circuits,” proposed a new circuit optimization technique to implement S-boxes—a core component of cryptographic algorithms—more quickly and efficiently.
 
The research team applied the proposed technique to various cryptographic algorithms—including the international standard AES and Ascon, the lightweight cryptographic standard developed by the U.S. National Institute of Standards and Technology (NIST)—and improved upon the existing state-of-the-art circuit performance. In particular, by optimizing while considering both the computational depth and hardware efficiency of cryptographic circuits, the technique is expected to enhance the efficiency of cryptographic operations in various environments, such as smart devices, the Internet of Things (IoT), and embedded systems.
 
Professor Kim Jong Sung stated, “This research is significant in that it has improved existing performance limitations by optimizing the core circuits of major cryptographic algorithms,” adding, “We will continue our research to enhance the efficiency of cryptographic implementation technologies through collaboration with domestic and international research institutions.”
 
This research was conducted with support from a research project at the “Institute for the Protection of Defense Technology” (Director: Professor Han Dong-guk), funded under the Ministry of Education’s Glocal Lab initiative, as well as from the “Development of Integrated Modes for Symmetric Cryptography to Overcome the Limitations of NIST Cryptographic Standards” project (Principal Investigator: Professor Kim Jong-sung), part of the Mid-Career Researcher Program funded by the Ministry of Science and ICT and the National Research Foundation of Korea.
 
Meanwhile, the DF&C Laboratory, led by Professor Kim Jong Sung, conducts various research projects in areas such as digital forensics, cryptanalysis, and cryptographic circuit optimization. Last year, the lab also presented research findings on S-box optimization for AES, SNOW3G, and Saturnin at CHES 2025.