WPI Cryptography Seminar Towards a Theory of Variable Privacy BY: Dr. Poorvi Vora, Hewlett-Packard Company, Corvallis, OR DATE: Monday, January 20, 2003 TIME: 10:00 AM PLACE: Atwater Kent, Room 218 ABSTRACT The traditional theory of security, with its focus on perfect secrecy, does not provide a satisfactory framework for the study of situations where information revelation bears a privacy cost and also provides a benefit. We define variable privacy as the use of randomization with user participation in the choice of parameters, and propose the beginnings of a theory for its study. Variable privacy enables the user, or a computational agent working on the user's behalf, to choose a level of interaction, based on a personal cost-benefit analysis of an instance of information revelation. Our theory is based on treating the randomization protocol as a channel for the information to be protected. We demonstrate a one-to-one correspondence between channel codes and a certain class of attacks. Shannon's theorems show the existence of very special attacks, and upper bounds on their efficiency. We use the bounds to motivate a privacy measure of randomization similar to one proposed the database literature, and thus provide connections between the theory of security and statistical privacy protection techniques. We are not aware of any other work that uses Shannon's theorems to construct the special attacks on cryptographic protocols. We are also not aware of any other work that connects error-correcting codes to attacks on randomization. DIRECTIONS: The WPI Cryptoseminar is being held in the Atwater Kent building on the WPI campus. Directions to the campus can be found at http://www.wpi.edu/About/Visitors/directions.html ATTENDANCE: The seminar is open to everyone and free of charge. Simply send me a brief email if you plan to attend. MAILING LIST: If you want to be added to the mailing list and receive talk announcements together with abstracts, please send us a short e-mail message. On the other hand, if you want to be removed from the list, just send a reply to this message with the word "remove" in the subject line. Regards, Berk Sunar and Bill Martin ______________________________________________________________ Berk Sunar, Assistant Professor Electrical & Computer Eng. Dept. Ph (508) 831 54 94 Worcester Polytechnic Institute Fx (508) 831 54 91 http://www.wpi.edu/~sunar http://ece.wpi.edu/research/crypt/ CRIS Laboratory ______________________________________________________________ --- end forwarded text -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire' --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com