In this part, we build on Part 2 and 3 to develop a protocol for verifiable blind evaluation of polynomials, which we will define shortly. In Part 5 we'll start to see how such a protocol can be used for constructing SNARKs, so bear with me a little bit longer for the connection to SNARKs.

This is what we call verifiable blind evaluation of a polynomial. The protocol in Part 2 gave us the first item but not the second. To get verifiability, we need an extended version of the Knowledge of Coefficient Assumption (KCA) that was presented in Part 3.