“The booklet under review is a comprehensive study that investigates the problem of querying encrypted data in smart grids and focuses on preserving data and query privacy, a topic that is rarely discussed, but is nevertheless of great importance. … the booklet is a self-contained and interesting study that can be used as a reference point in the domain for documentation and future research in the area.” (Adrian Atanasiu, zbMATH 1308.68012, 2015)