Base NaorPinkasOT Optimization with Elliptic Curves

[Gugi264]

I wrote an (optional) optimization for Naor Pinkas OT which uses elliptic curves instead of Big Integers.
The only problem is it adds bouncy castle as a dependency.
Is this a problem? Otherwisee I could make a PR.

[jonas-lj]

That sounds good! An extra dependency is not a problem for me, especially if it's just for the OT module (is it just for that module or for core?)

[Gugi264]

The extra dependency is just for the OT module