Universitas Gadjah Mada, Yogyakarta, Indonesia
July 24, 2025
Lecturing Session:
The 9th day of CIMPA SCHOOL 2025 began with a lecture by Dr. Adeline Roux-Langlois, who continued her discussion on cryptographic techniques. The session focused on the Short Integer Solution (SIS) problem and the Learning With Errors (LWE) problem. Dr. Roux-Langlois then introduced Regev’s encryption scheme, explaining its encryption mechanism using LWE and its associated security proof. The final part of her lecture covered signature schemes, including trapdoor-based signature schemes and schemes utilizing the Fiat-Shamir transformation.
In the following session, Dr. Elisa Lorenzo Garcia delivered a lecture on Coding Theory. She introduced the concepts of dual codes and self-dual codes, along with their fundamental properties. Dr. Garcia provided an illustrative example involving the dual of a Hamming code and concluded with a discussion on syndrome decoding, supported by a concrete example.
Exercise Session:
Participants spent the exercise session working through problems related to lattice theory and coding theory under the guidance of the speakers.
Extra Session:
An extra session was held in the afternoon where four participants gave short presentations to share their research interests and current work, fostering further collaboration and academic exchange.
The day ended with a Cultural Night. Participants enjoyed dinner at Heha Sky View, which offered a panoramic view of Yogyakarta. They then attended the spectacular Ramayana Ballet performance at Prambanan Temple, concluding the day with cultural enrichment and fellowship.
