I've proposed the PGP/PKI Clean Room as a topic in Outreachy this year. The topic will also be promoted as part of GSoC 2017.
If you are interested in helping as either an intern or mentor, please follow the instructions there to make contact.
Even if you can't participate, if you have the opportunity to promote the topic in a university or any other environment where potential interns will see it, please do so as this makes a big difference to the success of these programs.