Privacy preserving image processing is an active area of research that focuses on ensuring security of sensitive images stored in an untrusted environment like cloud. Hu introduced the concept of moment invariants that are widely employed in pattern recognition. The moment invariants are used to represent the global shape features of an image that are insensitive to basic geometric transformations like rotation, scaling and translation. In view of this fact, this paper addresses the problem of moment invariants computation in an encrypted domain. A secure Hu’s moments computation is proposed based on a fully homomorphic encryption scheme. This method may be employed for feature extraction without revealing sensitive image information in an untrusted environment. © 2018, Springer International Publishing AG, part of Springer Nature.