Every convex polytope has both a vertex and a halfspace description. T
he complexity of translating from the vertices to the halfspaces (conv
ex hull) or vice versa (vertex enumeration) remains an important open
problem in computational geometry. In this note we present families of
hard polytopes for algorithms using pivoting, constraint insertion, a
nd triangulation, and discuss techniques for estimating the difficulty
of a convex hull or vertex enumeration instance.