Fully homomorphic encryption (HE) refers to a class of encryption methods that allow computations (such as search and arithmetic) to be performed directly on encrypted data. The result of such a computation remains in encrypted form, which at a later point can be decrypted and revealed. Although the HE problem was first proposed in 1978, a solution wasn't constructed until 2009. With advances in computing power and the availability of easy-to-use open-source libraries — including SEAL, Lattigo, HElib and partially homomorphic encryption in Python — HE is becoming feasible in real-world applications. The motivating scenarios include privacy-preserving use cases, where computation can be outsourced to an untrusted party, for example, running computation on encrypted data in the cloud, or enabling a third party to aggregate homomorphically encrypted intermediate federated machine learning results. Moreover, most HE schemes are considered to be secure against quantum computers, and efforts are underway to standardize HE. Despite its current limitations, namely performance and feasibility of the types of computations, HE is worth your attention.
