The early days of experimental quantum cryptography.

This paper describes the first quantum cryptography experiment, performed at the IBM Thomas J. Watson Research Center in the summer of 1989 by Charles H. Bennett and the author. The apparatus and some of the lesser-known details of the experiment are illustrated and discussed, and quantum cryptography is discussed in the light of some of the more recent research. Also included as an appendix is a short essay about Bennett written by Rolf Landauer. [ABSTRACT FROM AUTHOR]