POSTER: Improving Anonymity of Services Deployed Over Tor by Changing Guard Selection

Abstract

Many P2P applications are emerging that use Tor to ensure anonymity of their users. Each user in such an application creates an onion service so that the user can receive requests from other users. Such large-scale use of onion services leak a lot of sensitive information to guards in Tor. The cause of these leaks is diversity in guards' resources and the guard selection algorithm in Tor that is designed to use guards' resources efficiently. We describe a preliminary approach for selecting guards which reduces the amount of sensitive information leaked to guards while using guards' resources with same efficiency. Experiments in the context of a P2P publish/subscribe application shows that the approach reduces information leaked to guards by 25%.