Global Fujitsu Distinguished Engineer

Hiroaki Sakai


I specialize in low-layer software areas such as operating systems and assembly. I have been involved in many activities outside the company with the idea that "information gathers around those who send information" and to "contribute to improving technology in the world in repayment for what I learned". I have developed open-source software, disseminated information through the website, exhibitions, seminars, books, magazine articles, and the like, and participated in various events and projects such as security camps.


  • Development activities (development, exhibition, talks, book authoring, etc.) for the original embedded OS, "KOZOS"
  • Assembly decoding for multiple CPU types (established a feeling-based decoding method for unknown assembly and decoded over 50 types, developed tools, gave talks, authored books, etc.)
  • Developed various open-source software: original shell (nlsh), original standard C library (nllibc), original C compiler (nlcc), original programming language (nll), original Unix-compatible environment (nlux)
  • SecHack365 trainer
  • SECCON Program Committee Member, Contest WG Leader
  • CODE BLUEopen in new window speaker (2017)
  • Low-layer software distribution activities (conceived and disseminated one of the great poets of assembler tanka poems, binary karuta playing cards and binary jokes (Evangelist), etc.)
  • Authored multiple magazine articles and books ("Introduction to Integrated OS Construction in 12 Steps", "Great Enthusiasm! Introductory Assembler", "Practical Linker and Loader Development Techniques", and many more.)

Value Creation

  • Technological proposals, design and development on platforms of our routers and switches.