This book consists of high-quality papers presented at the International Conference on Computational Science and Applications (ICCSA 2021), held at Maharashtra Institute of Technology World Peace University, Pune, India, from 10 – 11 December 2021. It covers the latest innovations and developments in information and communication technology, discussing topics such as algorithms, data structures and applications; wireless and mobile networks; computer networks and communications; natural language processing and information theory; cryptography and information security.