Hiroyuki Katsura

PhD student at The University of Tokyo

Hiroyuki Katsura (桂宏行)

I’m Hiroyuki Katsura, 2nd-year PhD student, supervised by Naoki Kobayashi in 3-year PhD course at Dept. of Computer Science, Graduate School of Information Science and Technology of The University of Tokyo.

Contacts

Email:
- University: katsura[at]kb.is.s.u-tokyo.ac.jp
- Gmail: moratorium08[at]gmail.com
GitHub: moratorium08
Linkedin

Research Interests

My main research interest is to propose analyses to enhance software reliability. This includes:

(Automated) Software verification
- Logic-based automated software verification (c.f. CHC solving)
- Refinement types
Software security
- Fuzzing

Publications

Hiroyuki Katsura, Naoki Kobayashi, and Ryosuke Sato. Higher-Order Property-Directed Reachability. ICFP 2023. [video]
Yuki Koike, Hiroyuki Katsura, Hiromu Yakura, and Yuma Kurogome: SLOPT: Bandit Optimization Framework for Mutation-Based Fuzzing, ACSAC 2022.
Kazuyuki Asada, Hiroyuki Katsura, and Naoki Kobayashi. On Higher-Order Reachability Games Vs May Reachability. RP 2022.
Hiroyuki Katsura, Naoki Iwayama, Naoki Kobayashi, and Takeshi Tsukada. A New Refinement Type System for Automated νHFLZ Validity Checking. APLAS 2020.

Education

Apr 2022 - Now: Doctor of Information Science Kobayashi Lab
Apr 2020 - Mar 2022: Master of Information Science Kobayashi Lab, Dept. of Computer Science, Grad School of IST, UTokyo
Apr 2016 - Mar 2020: Bachelor of Science, Dept. of Information Science, School of Science, UTokyo

Experience

Grants

JSPS (学振) Research Fellowship for Young Scientists DC2, Apr 2023 - Mar 2025 高階プログラム自動検証のさらなる発展と自動テストへの融合 (Developing Automated Higher-order Program Verification and Combination with Automated Testing): project detail(ja)

Internships

Feb 2021 - Aug 2022: Ricerca Security, Tokyo
- Studied fuzzing with reinforcement learning
Aug - Sep 2020: LINE corp, Tokyo
- Developed an automated update for hypervisors on OpenStack using Kubernetes Operator Pattern (blog post[ja]).
Aug 2017 - Jul 2018: Flatt Inc, Tokyo
- Developed a backend infrastructure for a live commerce app
- Designed a scalable live streaming infrastructure using GCP
Sep 2016 - Oct 2017: Unipro Inc, Tokyo
- Researched translation systems from natural language to “datastore representation” for knowledge.

Teaching Assistants

I have been a teaching assistant three times at Dept. of Information Science, School of Science, The University of Tokyo.

Sep 2022 - Feb 2023: Processor and Compiler Lab
Apr 2023 - Aug 2023: Functional and Logic Programming Lab
Sep 2020 - Feb 2021: Processor and Compiler Lab

Projects

Google Summer of Code, Libvirt organization as a Participant Mar - Aug 2019
- Developed Rust bindings for libguestfs, which provides a set of tools for manipulating and communicating with virtual machine disk images (archive).
osmium: an operating system written in Rust which runs on RISC-V
- Developed an operating system on RISC-V from scratch using Rust (article(ja), translated one by cb372).
- Repo: https://github.com/moratorium08/osmium (Stars +190)

CTF (Capture The Flag)

I have been playing CTFs as a member of an university team TSG whose team members are all from The University of Tokyo. Sometimes, I join in larger teams to compete large contests like DEFCON. I mainly play pwnable (binary exploit) and reversing.

Here are some of my achievements in CTF contests. Note that due to the collaborative nature of CTFs, my individual contribution varied from one CTF to another :)

As a member of TSG
- SECCON 2022: International Finalists
- CTFZone 2020: Finalists
- TokyoWesterns CTF 2020: 9th
- Codeblue CTF 2018: Finalists
- SECCON 2018 International Finals: Winner
As a member of other teams
- SECCON CTF Domestic Finals 2023: winner as a member of :)
- DEFCON CTF 2023: finalists as a member of undef1ned
- DEFCON CTF 2022: finalists as a member of ./V /home/r/.bin/tw
- Google CTF 2020(hackceler8): finalists as a member of I use bing

My CTF Challenges

I have created a lot of CTF challenges so far from easy one to harder one: please refer to this page　(TBD).

My favorite ones are

Random collection of my writeups of my challenges:

Other Activities

ISUCON

ISUCON is a Japanese contest held by LINE corp, where participants aim to fine-tune a given web service within set regulations. I have played ISUCON six times as a member of FetchDecodeExecWrite.

Security Camp

Hobbies

Apart from researching, I’m a big fan of

Capture The Flag (security competition), especially pwnable
Low-level programming
Brewing drip coffee “nicely”
Bouldering / Climbing
Board games

Hiroyuki Katsura (桂 宏行)