Funny--I came here for the same reason. My best guess is that they were trying to solve a deconvolution problem the naive way (by solving a huge linear system)

Funny--I came here for the same reason. My best guess is that they were trying to solve a deconvolution problem the naive way (by solving a huge linear system). I think the reference to polynomial factorization might have something to do with solving the problem by taking the Z-transform of both sides, and then having to divide the resulting polynomials and invert the transform.