  Major cloud providers such as Amazon, Google and Microsoft provide nowadays
some form of infrastructure as a service (IaaS) which allows deploying services
in the form of virtual machines, containers or bare-metal instances. Although
software-based solutions like homomorphic encryption exit, privacy concerns
greatly hinder the deployment of such services over public clouds. It is
particularly difficult for homomorphic encryption to match performance
requirements of modern workloads. Evaluating simple operations on basic data
types with HElib, a homomorphic encryption library, against their unencrypted
counter part reveals that homomorphic encryption is still impractical under
realistic workloads.

Distributed, Parallel, and Cluster Computing