The10thintheseriesofIMAConferencesonCryptographyandCodingwasheld at the RoyalAgricultural College, Cirencester, during 19 21 December 2005. As usual, the venue provided a relaxed and informal atmosphere for attendees to discuss work and listen to the collection of talks. The program consisted of four invited talks and 26 contributed talks. The invitedtalkswheregivenbyTuviEtzion, UeliMaurer, AlfredMenezesandAmin Shokrollahi, and three of these invited talks appear as papers in this volume. Special thanks must go to these four speakers as they helped to set the tone, by coveringall the areasthe...