simsam:
Sorry i think i didnt use the correct word, i should have used technique instead of requirement.
Though what you're saying is absolutely correct, the thing is that my supervisor has told me to use PBC here, i cant use an alternative.Yes i understand that asymmetric crypto is more heavy weight, is there no way to implement this at all? What if i were to change from UNO to MEGA? Even that wouldnt suffice?
No, its ~ 10000 times slower than stock computer hardware, its an 8-bit microcontroller.
We are talking 3 to 5 orders of magnitude difference in performance, basically, between a
small micricontroller and a general purpose processor, considering memory, speed or transistor count.
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.