This book constitutes the revised selected papers of the10th International Workshop on Data Privacy Management, DPM 2015, and the 4thInternational Workshop on Quantitative Aspects in Security Assurance, QASA2015, held in Vienna, Austria, in September 2015, co-located with the 20thEuropean Symposium on Research in Computer Security, ESORICS 2015. In the DPM 2015 workshop edition, 39 submissions werereceived. In the end, 8 full papers, accompanied by 6 short papers, 2 positionpapers and 1 keynote were presented in this volume. The QASA workshop series responds to the increasingdemand for techniques to deal with quantitative aspects of security assuranceat several levels of the development life-cycle of systems and services, fromrequirements elicitation to run-time operation and maintenance. QASA 2015received 11 submissions, of which 4 papers are presented in this volume aswell.