This book constitutes the revised selected papers of the 6th International Conference on Information Systems Security and Privacy, ICISSP 2020, held in Valletta, Malta, in February  2020.  The 11 full papers presented were carefully reviewed and selected from a total of 125 submissions. The papers presented in this volume address various topical research, including new approaches for attack modelling andprevention, incident management and response, and user authentication andaccess control, as well as business and human-oriented aspects such as data pro-tection and privacy, and security awareness.