I have been going through a huge amount of papers to find a simple and a practical method to compare integer numbers without revealing their original values. I know that this falls within the area of secure multi party communication framework. However, I have very limited knowledge in cryptography and I can not really understand much of what the papers explains.
I have already tested the viff (viff.dk/) framework but the computation cost is quite high to compare just 5 numbers (about 500 milliseconds). I am looking for a solution with minimum security guarantees but low computation overhead. I would be grateful if someone point out a simple solution to start with or even an implementation which I can use. I know that my question may seem quite general, but I am kind of lost here and any pointers would help.
We would like to compare offers of different ISPs (internet service providers) in order to provide the best service to a customer (bidding). The ISPs don't want their offers to be revealed to the other ISPs but they want to know which one of them wins (the one with the best offer). They don't want to use a third party to do the comparison, they want to do it in a multi party fashion. The information provided by the ISPs currently is just a single integer of 8-bits length. The goal is to find the biggest integer. I don't know if this include multiple operations or just a single one !! ... And I guess it needs inequalities ... since this comparison needs to be done as fast as possible within 10th of milliseconds and we assume that the ISPs would be mostly honest, we are looking for as simple and as practical as possible protocol to do it. Our concern is is speed more than the security.