This book constitutes the refereed proceedings of the 15th International Conference on Trust, Privacy and Security in Digital Business, TrustBus 2018, held in Regensburg, Germany, in September 2018 in conjunction with DEXA 2018. The 15 revised full papers presented were carefully reviewed and selected from 29 submissions. The papers are organized in the following topical sections: Permission models and cloud, privacy, proactive security measures, and cyber physical systems.