Enlisting ISPs to Improve Online Privacy: IP Address Mixing by Default #

This paper proposes the address hiding protocol (AHP), a relatively simple mechanism that is meant to improve Internet users’ privacy. The protocol is meant to be deployed by ISPs, and works by substituting the IP address:port pairs of clients. The size of an ISP’s address pool becomes the anonymity set for its clients. AHP is meant to be a pragmatic middle ground between next-generation Internet architectures and overlay anonymity networks. Clients don’t need to support AHP—it works transparently for them. If the security properties are not strong enough for clients, they can also layer another anonymity network on top of AHP. It’s great to see that the authors thought about real-world deployment. They discuss incentives for ISPs and practical issues such as long-lived flows and supporting P2P applications.