This book constitutes the refereed proceedings of the18th International Conference on Information Systems Security, ICISS 2022, held in Tirupati, India, during December 16-20, 2022 The 8 full papers and 5 short papers included in this book were carefully reviewed and selected from 55 submissions. They were organized in topical sections as follows: ostinato: cross-host attack correlation through attack activity similaritydetection; DKS-PKI: a distributed key server architecture for public keyinfrastructure;generating-set evaluation of bloom filter hardening techniques in privaterecord linkage; etc