My last week surprisingly didn’t involve any more hardware and I had opportunity to play again with some good old C. The task for this week was to write the missing software part for the ECDSA, that is the whole algorithm for signature generation and verification (keeping in mind that scalar point multiplication and SHA-1 portion is already taken care of in hardware). The only difficulty was that numbers are well above the int range so I had to write my own big number arithmetic (because it’s a microprocessor software, not PC, I couldn’t use any freely available library). Eventually of course everything worked (I can say by comparing with examples provided here http://www.secg.org/collateral/gec2.pdf)
I officially finished my internship at Aeste. I’m going to miss my boss and my coworkers. I had a really great time here, I got some experience and what is even more important I got some interest in the topic giving me a better picture what to do in the future. Now only three more weeks to relax and explore Southeast Asia a little bit, before I start a new semester.