Tor low-bandwidth

The Tor anonymity system is currently only usable by internet users with high-bandwidth connections. Upon start of a Tor client, a large file with all Tor server descriptions is being downloaded. This "Tor Directory" file enables the client to pick from the available mix-servers in the Tor network. This Directory file is too large for users on modem lines or on mobile data networks (like GPRS) as it gets downloaded each time a user logs in, taking 10 to 30 minutes over a slow connection. Therefore, Tor is not usable by modem and mobile users.

One of the major goals of the Tor project is to provide secure anonymous internet access to users in repressive states. These location often have very slow internet connections to the outside world. By enabling these users to use the Tor network, significant progress can be made towards free communication and free information in these countries.

An evolution of the Tor protocol is proposed to reduce the initial download size. The new Tor protocol version should change the way a client receives the information for its Tor circuit setup in such a way, that the initial download can be performed over a slow modem line in less then three minutes.

The work to be conducted under the proposal is split into two major deliverables, with the end goal of having the protocol change production ready and propagated to the Tor users within a timeframe of less then 8 months. The resulting software will be published under the GPL license, like the rest of the Tor code. All deliverables will be fully public.