Lattice cryptography - although I wouldn't want to rely on it in 2015 - is quite flexible and does support such advanced systems. Also, homomorphic encryption a

Lattice cryptography - although I wouldn't want to rely on it in 2015 - is quite flexible and does support such advanced systems. Also, homomorphic encryption and zero-knowledge proofs are almost entirely unused (and, due to the enormous overhead of FHE in particular, unusable) in practice. We'll deal.