On the feasibility of short-lived dynamic onion services

Abstract

Tor onion services utilize the Tor network to enable incoming connections on a device without disclosing its network location. Decentralized systems with extended privacy requirements like metadata-avoiding messengers typically rely on onion services. However, a long-lived onion service address can itself be abused as identifying metadata. Replacing static onion services with dynamic short-lived onion services may be a way to avoid such metadata leakage. This work evaluates the feasibility of short-lived dynamically generated onion services in decentralized systems. We show, based on a detailed timing analysis of the onion service deployment process, that dynamic onion services are already feasible for peer-to-peer communication in certain scenarios.