1. A method to facilitate privacy-preserving collaboration for mitigating network threats, comprising: receiving encrypted data sets from a plurality of entities, wherein the data sets including data describing threats to network security; performing private set intersection for the encrypted data sets; computing one or more metrics based on results of the private set intersection computations; generating a similarity matrix based on the one or more metrics; and returning one or more similarity values from the similarity matrix to one or more entities of the plurality of entities.