JOHN B. ANDERSON holds the Ericsson Chair in Digital Communications at Lund University, Sweden. He was formerly a professor at Rensselaer Polytechnic Institute. He is a Fellow of the IEEE and is a recipient of the Humboldt Research Prize and the IEEE Third Millennium Medal. His research and consulting practice concentrates on communication algorithms and bandwidth-efficient coding. ROLF JOHANNESSON is Professor of Information Theory at Lund University, Sweden, and a Fellow of the IEEE. He was awarded the honor of Professor, honoris causa, from the Institute for Information Transmission Problems, Russian Academy of Sciences. His research interests include information theory, error-correcting codes, and cryptography.