Fully Homomorphic Encryption: Blindfold Computations in the Cloud

Fully Homomorphic Encryption (FHE) schemes are probabilistic public key encryption schemes that allow anyone to compute functions of ciphertexts without any secret knowledge. For instance, given a FHE ciphertext C of a plaintext m, any user may learn another ciphertext C' which encrypts f(m), for a function f of his choice. This property has been referred to as the "Holy Grail of Cryptography" and it was first proved feasible using ideal lattices by C.Gentry in his 2009 Ph.D. thesis. We will first give an overview of his construction, and then jump in time to describe fancy properties of recent FHE schemes: identity or attribute based FHE schemes, Multikey FHE schemes, Key-homomorphic FHE schemes, and discuss some open problems and applications.