This open access book presents selected papers from International Symposium on Mathematics
Quantum Theory and Cryptography (MQC) which was held on September 25-27 2019 in Fukuoka
Japan. The international symposium MQC addresses the mathematics and quantum theory underlying
secure modeling of the post quantum cryptography including e.g. mathematical study of the
light-matter interaction models as well as quantum computing. The security of the most widely
used RSA cryptosystem is based on the difficulty of factoring large integers. However in 1994
Shor proposed a quantum polynomial time algorithm for factoring integers and the RSA
cryptosystem is no longer secure in the quantum computing model. This vulnerability has
prompted research into post-quantum cryptography using alternative mathematical problems that
are secure in the era of quantum computers. In this regard the National Institute of Standards
and Technology (NIST) began to standardize post-quantum cryptography in 2016. This book is
suitable for postgraduate students in mathematics and computer science as well as for experts
in industry working on post-quantum cryptography.
