Elliptic Curve Cryptography Implementation

I need to implement the code on Arduino Mega 2560 or uno. I have already implemented the basic functions in C on Mega. Now as per given algorithm the functions need to arranged methodically and accordingly called to get the output. Since the lower level functions are all done so it won't be too time consuming to get the main code working for someone proficient in Arduino and c coding. I need a cross platform implementation between android and arduino. I used microecc implementation i could be able to sign and verify. But i wanted the verify function independently for arduino. I will sign the string from arduino with private key and i want it to be verifyed in arduino by public key. If you have talent you will get this job.