This book constitutes the revised selected papers from the 22nd International Conference on Information Security Applications, WISA 2021, which took place on Jeju Island, South Korea, during August 2021. The 23 papers included in this book were carefully reviewed and selected from 66 submissions. They were organized in topical sections as follows: machine learning security; cryptography; hardware security; and application security.

This book constitutes the revised selected papers from the 22nd International Conference on Information Security Applications, WISA 2021, which took place on Jeju Island, South Korea, during August 2021. The 23 papers included in this book were carefully reviewed and selected from 66 submissions. They were organized in topical sections as follows: machine learning security; cryptography; hardware security; and application security.