Encryption with regards to what?
Safari, Chrome, I.E., Firefox, etc. all use encryption.
The Prime Number calculations use the same CPU instruction set that a tablet uses 100% of the time while it is being used. Even when you are playing a game, the CPU is making a billion+ calculations per second controlling every aspect of the game and building the 3D triangle wire frames for the images (the GPU adds the skins, Z-axis, shading, lighting effects, edge anti-aliasing, etc), so the Prime Number calculation results are very important.
My iPad 3 shows its CPU weakness when I play Zen Pinball. As I progress further into the game and every light, special effect, and multiple balls are in play, it slows down to where the ball is moving in slo-mo and the flipper response time becomes nearly unplayable. The same game and tables work at full speed on my Nexus 7; as I would expect with a Prime Number calc result nearly 4 times faster than my iPad 3 and twice as fast as the iPad 4.