It's not a trivial task - think about how hard it is to detect computer viruses in a computer. Then we also know that homomorphic encryption is possible in pri

It's not a trivial task - think about how hard it is to detect computer viruses in a computer. Then we also know that homomorphic encryption is possible in principle, where from the outside it's thought to be impossible to figure out what computation goes on inside the algorithm (for example searching for a simulation)