This system was built as a class project and is to be used for educational purposes only! This system is not intended for any production usage as a secure messaging service!

This is a reproduction of the Vuvuzela system for COS 518 at Princeton University.

Vuvuzela [1] is a secure messaging system that protects client metadata. The system maintains very strong privacy guarantees compared to the anonymity system we learned about in class. Even if all but one of the servers are controlled by a malicious party, Vuvuzela completely hides client data and metadata.

Building and running

This code uses the cargo build system. To build, run

$ cargo build

This produces six binaries: setup, head_server, intermediate_server, deaddrop_server, testclient, and client, each located in the target/debug subdirectory.

This project was tested and confirmed to build/work with rustc 1.35.0-nightly (70f130954 2019-04-16).

Setup and key distribution

The setup binary must be run prior to using the system. It produces private and public keys and places them in the keys subdirectory. To run the system, the appropriate key files must be present. In particular:

• All clients and servers need server public keys keys/server/*.pk
• Each client needs the private and public keys keys/client/<client id>.*
• Each client needs the public keys of its conversants keys/client/<conversant id>.pk We do not provide a means to distribute keys to different parties, but it suffices to copy the files.

Running the server

All three server binaries must be run. For a list of options, run

$ head_server -h

The servers must be started in reverse order, starting with the deaddrop server, then the intermediate server, and lastly the head server.

Running the client

The testclient binary can be used to simulate many users and reproduce our data. It too has options

$ testclient -h

The client binary is still experimental, but is intended to provide command line input and output to the messaging system. A user must specify the uid of the 'local' user and of the remote user being dialed within the system to run the client.

$ cargo run --bin client -- -n 1 -d 0

For example, would run the client with UID 1, dialing the client with UID 0.

Tests

Unit and integration tests can be run with

$ cargo test

References

[1] Jelle van den Hooff, David Lazar, Matei Zaharia, and Nickolai Zeldovich. Vuvuzela: Scalable private messaging resistant to traffic analysis. In Proceedings of the 25th Symposium on Operating Systems Principles, SOSP ’15, pages 137–152. ACM, 2015.