I would like to introduce our project "Crux", which enables the computation of privacy preserving statistics on sensitive data.
The project was developed at University College London (UCL) by me, in close collaboration with George Danezis.

"Crux" was designed with Tor hidden services in mind (in accordance with this Tor Tech Report), but it can be applied on various kinds of data (given an appropriate parser).

It supports three statistics (i.e. mean, median, variance) and its threat model is compatible Tor's (see technical document below).
Currently, we don't have a parser specific for the data collected by the Tor relays, but we plan to keep adding functionality.

The source code can be found here: https://github.com/mavroudisv/Crux

The theoretical background, threat model, security argument and technical details can be found here: link

Ideas, comments, feedback much appreciated!

Vasilis

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