Challenge 2: Humilation-Free Partnering

In Lecture 11, we considered the problem of finding partners to work with on Problem Set 3, without the fear that unrequited partnering desires would be revealed. The protocol presented had a number of flaws, however. Among them, anyone could guess possible partner requests and confirm if they are true or false; anyone could enter a bogus partnership request into the database; and there is no way of preferentially requesting partners.

A useful starting point may be A Private Matchmaking Protocol, Kan Zhang and Roger Needham.

A solution to this challenge that satisfies all the requirements (without using a trusted third party) is worth 100 points (one problem set). Some discretionary credit may be given for good solutions that satisfy some of the requirements.

University of Virginia Department of Computer Science CS 588: Cryptology - Principles and Applications

David Evans evans@virginia.edu