I once heard that anywhere we try and get extra performance, there is probably the possibility for a side channel, and I think that's true. Any optimisation in

I once heard that anywhere we try and get extra performance, there is probably the possibility for a side channel, and I think that's true. Any optimisation in such a complex system is likely to have some sort of side effect, given that simply timing is often sufficient as a side channel it is going to be difficult to eliminate this class of attack.