IWSEC 2019

August 28 (Wed) - 30 (Fri), 2019
Tokyo Institute of Technology, Tokyo, Japan

Special Session of Mathematics and Information Security (M&IS)

This is a new session aiming to share recent trends of relationship between mathematics and information security. In this session, we invite two distinguished researchers on information security based on mathematics. At this session, we would like to discuss the future progress of both communities for developing information systems based on mathematics.

This session is organized by the AIMaP*1 project, supported by MEXT*2. The aim of the project is extending research areas and activities related to mathematics by cooperating IMI*3 and 12 mathematics research institutions in Japan.

*1 Advanced Innovation powered by Mathematics Platform. https://aimap.imi.kyushu-u.ac.jp/
*2 Ministry of Education, Culture, Sports, Science and Technology, Japan.
*3 Institute of Mathematics for Industry, Kyushu University, Japan.


The following are the invited speakers:

Dr. Kazue Sako

Distinguished Researcher, Security Research Laboratories, Central Research Laboratories, NEC Corporation

Mathematics and Cryptography for Society


In the age of digital transformation, not only industry but also society as a whole will be largely impacted from information and communication technology (ICT). Yet these technologies can be misused to harm individuals and society, by being insecure or unfair. In the physical world, we had been using physical objects and its limitation to disable malicious activities to achieve more security and fairness. However, in the digital world, these limitations are useless and thus the system is apt to be misused. Cryptography provides a tool to create such limitations in the digital world, as it studies mechanisms to control information flow or restrict procedures in digitalized systems. Therefore it is important to design secure and fair systems for society using cryptography. Mathematics is necessary to to make sure that cryptographic protocols and primitives achieve the designed criteria.

In this presentation, we will discuss the design of blockchain technology used in Bitcoin as an example of societal system that decentralizes power to achieve fairness, together with some of the activities within Japan to bridge mathematics and cryptography.

Prof. Carlos Cid

Professor in Information Security, Royal Holloway University of London, UK, and Simula UiB, Norway

Domain Specific Ciphers


In this talk we discuss symmetric-key algorithms specifically designed for use in particular domains or novel applications. While block ciphers are perhaps the best understood and widely used class of cryptographic algorithms, most conventional algorithms have been designed to encrypt bit-string messages for transmission and storage. Furthermore, they aimed for efficient implementation on standard CPUs and in hardware. Recent advances in cryptography have on the other hand increased the number and range of applications in which symmetric-key ciphers can be used, or required: for example, a block cipher may be needed to encrypt messages respecting a specific format; they may be used as building block of applications which would benefit from low multiplicative circuit depth; or have features that facilitate secure obfuscation. Despite its attractive features, AES and most conventional block ciphers may not be particularly suitable for these applications or platforms.

We provide an overview of the main recent developments in this area, focusing mainly on the design and analysis of algebraic ciphers proposed for supporting advanced applications, such as Zero-Knowledge proofs. These ciphers aim to minimise the number of multiplications on a large field, in order to improve performance of ZKPs. However their simple algebraic structure may make them particularly vulnerable to algebraic attacks.