This page was last updated in May 2018.


Research on the I2P Network

Research plays a key role in both maintaining the security and integrity of the I2P network, as well as opening doors for more impactful future development.

There is a large research community investigating a wide range of aspects of anonymity. For a current and comprehensive list of relevant papers, see the Free Haven Anonymity Bibliography. I2P benefits from much of the research into Tor and onion routing, but there is little dedicated research interest into the theory behind I2P, and the choices and tradeoffs that the network makes. This presents a unique opportunity for original research.

A list of known published papers about I2P is available here.

This page outlines the most needed fields of research, notes to potential researchers, general safety guidelines as well as an expanding list of open research questions.

Notes to Researchers:

Defensive Research

While all research on the I2P network is beneficial and appreciated, there are certain areas that are more in need than others. Most research focuses on testing offensives against anonymous software, and this is further reinforced by the incentives in academic institutions. The project would appreciate research and testing that will support fortifying the I2P network.

Offensive and Analytic Tests

If you've decided on a research topic that aims to hands-on investigate the I2P network or solve a problem of large proportions we ask you to please communicate your ideas to the development team, the sooner the better. I2P is under constant development and a significant amount of roadmapping occurs, therefore your problem may have already been identified and flagged for update or patch. In the unlikely event you are conducting testing that overlaps with / would be of interest to another research project already in motion, we are also able to make you aware of this (with their permission, of course), and possibly open the door for collaboration. There is also a chance that the test itself may significantly harm the network or regular users, and the team may have ideas or suggestions to mitigate that risk and increase the safety of your testing.

Research Ethics & Testing the Network

General Guidelines

  1. Consider the benefits and risks - is there any doubt that the research provides more value than danger?
  2. If the research can be done on a test network then that is the preferred method
  3. If you must operate on the live network, the safest route is only collecting data about yourself
  4. If you need 'bigger data', It is recommended to first see if you can use data sets from previous experiments or other third party resources is recommended
  5. If you must collect data on the live network, ensure it is safe for publication and collect as little as possible
  6. After testing and before publish, review that all data which is to be published publicly is not intended to be private by the originator

Using a Test Network to Attack I2P

I2P can be run as a separate test network by controlling the locations that a new router reseeds from so that it only finds other test routers. The standard mode of operation is to have one JVM per router instance; hence running multiple copies of I2P on a single machine is inadvisable, both due to the potential resource drain and the certain port conflicts. To better facilitate setting up small test networks, I2P has a multirouter mode which enables multiple distinct routers to be run in the same JVM. MultiRouter can be started from the i2p base directory by running the below command.

env CLASSPATH=$(find lib/ -name *.jar | paste -s -d ':') java net.i2p.router.MultiRouter 25

Additionally, I2P can be started in a virtual network mode. This mode disables all transports, allowing the router to be tested in isolation without network traffic. To enable this mode, add i2p.vmCommSystem=true to the router.config before starting.

Testing on the Live I2P Network

As stated above in the researcher notes, please contact us before you commence your testing. While we do not discourage researchers from responsibly testing their ideas on the live network, if an attack becomes apparent and we don't have any line of communication then we will end up taking countermeasures which could interfere with the test.

Router Family Configuration

As of release 0.9.25, I2P supports a router family configuration. This provides researchers who run multiple routers with the means to publicly identify those routers. In turn, this helps the I2P project understand that these routers are not running an attack on the network. It also will prevent other routers from including multiple routers of the family in a single tunnel, which could lead to deanonymization. Routers that appear to be colluding but do not have a declared family may be assumed to be an attack on the network, and may be blocked. The best way to ensure the success of your research project is to work with us directly.

A router family shares a private key so that participation in the family cannot be spoofed. To configure a router family, click on the 'I2P Internals' link in the router console, and then on the 'Family' tab. Follow the instructions there to generate the private key for the first router in the family. Then, export the key from that router, and import it to other members of the family.