Input: a set of points
Output: polynomial that passes through all points of Input
Here, since the input are just two numbers, I don't think it is polynomial interpolation.
This is such a natural way to introduce it! I remember that I didn't fully grasp the concepts of what a 'base' is until my first year in college.
Luckily for crypto, the coefficients used in a properly implemented scheme are so large as to not be vulnerable to such an attack.