MarkT:
No, its ~ 10000 times slower than stock computer hardware, its an 8-bit microcontroller.For a small microcontroller an efficient block-cipher based MAC is feasible, asymmetric crypto systems are not.
Even on the Due or similar with 32 bit architecture you'll find the performance is dissappointingly slow, and
typically you'd only use asymmetric crypto to set up a secure channel using standard symmetric crypto, so that the heavyweight step only
has to happen once (or perhaps once per day or similar). I recommend reading "Cryptography Engineering: Design Principles and Practical Applications" by Ferguson/Schneier/Kohno.
Thank you for your detailed answer. I will discuss this with my supervisor.
So the conclusion being that running an asymmetric crypto (PBC) will not be possible on any arduino board. I will have to move to something else.
Thank you again for your help.