This book constitutes the refereed proceedings of the 4th IFIP WG 11.11 International Conference, IFIPTM 2010, held in Morioka, Japan, in June 2010. The 18 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 61 submissions. The papers are organized in topical sections on privacy and trust; security through trust; trust models and management; trust models; and experimental and experiential trust.