Experiments on the Gentry-Halevi somewhat homomorphic scheme

We have implemented the somewhat homomorphic scheme from (16). We examined this scheme in the same way as mentioned in (16) and extend the results for a wider set of parameters and also increased the number of repetitions for each test. We focused on the dependencies between the largest supported degree and various parameters of the cryptosystem, specially also the encryption parameter q. We show that the probability q significantly influences the overall effectiveness of the scheme and that the growth of the supported degree doesn't grow linearly with the parameter t (strictly) and we give an explanation for this fact.