Figure 2 in the Verifiable Computation - Pinocchio

Question

I am reading the Pinocchio paper (verifiable computation): http://research.microsoft.com/pubs/180286/pinocchio.pdf

The paper is rather hard for me. For the Figure 2, I guess $v_1(x)$ should be $(r_6-r_5)^{-1}*(x-r_5)$, and the rest can be found similarly. Is this right? If yes, then how do we determine $r_5$ and $r_6$ when we generate the keys (evaluation and verification). Since we will have to calculate $v_k(s)$ etc.

Thanks for help me to understand it!

Answer 1

Yes, this is correct. The $r_i$ are arbitrary elements of the base field, their values are unimportant as long as they are all distinct.