Background: For the last few years the International Workshop on Practice and Theory in Public-Key Cryptography has been the main annual workshop focusing on research on all as- pects of public-key cryptography. The rst workshop was organized in 1998 in Japan. Other PKCs have taken place in Australia, France, Japan, South Korea, Singapore, and USA. Since 2003, PKC is an IACR workshop. PKC has attracted papers from world-renowned sci- entists in the area. Topics of Interest: The topics of interest are all aspects of public-key cryptography including theory, design, analysis, implementation, and applications of public-key cryptography. Conference Venue: PKC 2005 will be held at the Congress house in Les Diablerets, Switzer- land. Les Diablerets is a little village located in the Alps at the foot of a glacier. The village offers several winter sport activities such as ski, snowboard or sledging. The top of the glacier can be visited taking a cable-car at any time of the year. More information about Les Diablerets is available on http://www.diablerets.ch. Social Events: The social program includes a welcome reception, a free afternoon and a ban- quet. The banquet will be held at the Eurotel Victoria. Some additional social events will be proposed such as sledging followed by a cheese fondue. Registration: Details about workshop registration are on the PKC 2005 website. Hotel regis- trations should be done separately and since January is a busy period an early hotel booking is strongly recommended. Accommodation: The principal hotel in Les Diablerets is the Eurotel Victoria. This four stars hotel is located at about 200 meters of the Congress house. For some information or a booking at the hotel and cancellation policy, you can directly contact the hotel Eurotel Victoria by phone, fax, email or directly from the web. Mention that you are a participant of PKC 2005! Web Address: http://www.eurotel-victoria.ch/lesdiablerets/frameseteng/frameset.htm