Privacy-Preserving Publish/Subscribe: Efficient Protocols in a Distributed Model

We consider the problem of modeling and designing efficient and privacy-preserving publish/subscribe protocols in a distributed model where parties can act as publishers or subscribers or both, and there are no brokers or other types of parties. The problem is particularly challenging as privacy demands on such protocols come with efficiency limitations; most notably, the publisher must send messages as long as the publications to all parties, and the cryptographic techniques to perform the publish/subscribe match need to be based on asymmetric cryptographic operation which are known to be less efficient than their symmetric counterpart.