School: Introduction to Isogeny-based Cryptography (TSVP-TP25IC)

Title: "Introduction to Isogeny-based Cryptography"

Abstract: Isogeny-based cryptography is a fast-moving field, and recent developments have introduced several new techniques, making the barrier of entry particularly high for young researchers wishing to work in the field. To aid new researchers in the field is the aim of this "summer" school, which introduces all of the many essential tools that are used today. Among the topics to be covered are the correspondences between ideals and isogenies that give rise to both the Deuring correspondence, which is an essential part of protocols such as SQIsign, and the class group action on CM curves and oriented supersingular curves, which gives other cryptographic primitives such as CSIDH and SCALLOP. Further, higher dimensional abelian varieties and isogenies between these have recently become an integral part of isogeny-based cryptography, providing huge improvements to many existing protocols, as well as creating new protocols.

This school is part of the Thematic Program on "Isogeny-Based Cryptography (TP25IC)" which is held at OIST from January 13 to February 28, 2026.

Registration

Registration form* (Deadline: February 4, 23:59 JST) 
* regular registration has closed. Now only online attendance and OIST members 
Registration fee: 8000 JPY, collected in cash (free for members of OIST)

Confirmed Speakers

Andrea Basso (IBM Research Zurich)
Wouter Castryck (KU Leuven)
Luca De Feo (IBM Research Europe)
Tomoyoshi Ibukiyama (Osaka University)
Hiroshi Onuki (University of Tokyo)
Lorenz Panny (Technische Universität München)

Schedule

Mon, February 9, 2026: "Mathematical foundations of isogeny-based cryptography"
09:15 - 09:20 Welcome
09:20 - 10:50 Mathematical foundations of isogeny-based cryptography I
(Luca Defoe)
10:50 - 11:15 Group Photo & Coffee break
11:15 - 12:45 Mathematical foundations of isogeny-based cryptography II
(Luca Defoe)
12:45 - 14:00 Lunch Break
14:00 - 15:30 Exercise
15:30 - 16:00 Coffee break
16:00 - 17:30 Exercise

Tue, February 10, 2026: "Higher dimensional isogenies"
09:15 - 10:45 Higher dimensional isogenies I (Wouter Castryck)
10:45 - 11:00 Coffee break
11:00 - 12:30 Higher dimensional isogenies II (Wouter Castryck)
12:30 - 14:00 Lunch Break
14:00 - 15:30 Exercise
15:30 - 1600 Coffee break
16:00 - 17:30 Exercise 

Wed, February 11, 2026
09:15 - 17:30 Excursion

Thu, February 12, 2026: "PKE (FESTA, POKE) and Signature (SQIsign)"
09:15 - 10:45 PKE and signatures I (Andrea Basso)
10:45 - 11:00 Coffee break
11:00 - 12:30 PKE and signatures II (Andrea Basso)
12:30 - 14:00 Lunch Break
14:00 - 15:30 Exercise
15:30 - 1600 Coffee break
16:00 - 17:30 Special Talk "A Survey on Super Singular Abelian Varieties” (Tomoyoshi Ibukiyama) 

Fri, February 13, 2026: "Group Action" and "Algorithms for solving isogeny problems"
09:15 - 10:45 Isogeny Group Actions (Lorenz Panny)
10:45 - 11:00 Coffee break
11:00 - 12:30 Algorithms for solving isogeny problems (Hiroshi Onuki)
12:30 - 14:00 Lunch Break
14:00 - 15:30 Exercise
15:30 - 1600 Coffee break
16:00 - 17:30 Exercise
17:45 - 18:45 Free Discussion (optional)

Venue

L5D23, Located on floor D of Lab 5, on OIST campus (click here for campus information)

※ Please note that this event may be recorded and the videos uploaded. In addition, photos may be taken during the event. These are intended for publication online (the OIST website, social media, etc.)※ 

Travel Arrangement/Accommodation

※ To attend the entire symposium, we strongly encourage the participants to arrive on February 8 and schedule their departure no earlier than February 14. 

※ Note that access to OIST by public transport can be difficult. We recommend staying in hotels in the south of Onna village or Ishikawa, and walk or share a taxi with other participants to come to the venue at OIST's Lab 5.

※ OIST may be able to provide travel support for a limited number of participants. Young researchers, participants from underrepresented groups, and those who contribute to the school will be prioritized. 

Additional Information

Here is some supplementary information that participants may find useful

• Website of Okinawa Institute of Science and Technology (OIST): https://www.oist.jp/

• OIST campus map: https://www.oist.jp/campus#paragraph-3410

• Access (taxi/car/bus) to OIST campus: https://www.oist.jp/campus/access-map

• Getting around Okinawa (intended for the Visiting Program's long-term guests): https://www.oist.jp/visiting-program/getting-around

• OIST Resource Centre: https://www.oist.jp/resource-center

• Airport shuttle: https://www.okinawa-shuttle.co.jp/en/

• Okinawa marine safety: https://www.portal.marinesafety.okinawa/

• Okinawa travel guide: https://visitokinawajapan.com/