This talk is based on hep-th/9605234. The two main points are:
(1) We address the issue of time asymmetry associated with the existence of an event horizon of a black hole. Any microscopic model of a black hole based on time-symmetric laws must explain how the black hole cannot decay at the classical level but can absorb nevertheless. We show how this happens in the D-brane models of five dimensional charged black holes in the limit of large mass. The fact that large mass is required also indicates that the time asymmetry property based on classical gemotry is only approximate.
(2) We calculate the finite non-zero cross-section for absorption starting from the D-brane models and show this to be proportional to the area. We also calculate the classical absorption cross-section using scalar wave equation in the black hole background and show this to be equal to the area.