Psst, Over Here: Communicating Without Fixed Infrastructure

TitlePsst, Over Here: Communicating Without Fixed Infrastructure
Publication TypeTechnical Report
Year of Publication2012
AuthorsCallahan, T., Allman M., & Rabinovich M.
Other Numbers3229

This paper discusses a way to communicate without relying on fixed infrastructure at some central hub. This can be useful for bootstrapping loosely connected peer-to-peer systems, as well as for circumventing egregious policy-based blocking (e.g., for censorship purposes). Our techniques leverage the caching and aging properties of DNS records to create a covert channel of sorts that can be used to store ephemeral information. The only requirement imposed on the actors wishing to publish and/or retrieve this information is that they share a secret that only manifests outside the system and is never directly encoded within the network itself. We conduct several experiments that illustrate the efficacy of our techniques to exchange an IP address that is presumed to be a rendezvous point for future communication. Additionally, we describe a wider channel that can be used to transmit an SMS- or Twitter-like 140-character message.


This work was partially supported by funding provided through National Science Foundation grants CNS: 0433702 (“Center for Internet Epidemiology and Defenses”); CNS: 0831821 (“Relationship-Oriented Networking”); CNS: 0831535 (“Comprehensive Applications Analysis and Control”); and CNS: 0831780 (“Relationship-Oriented Networking”).. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors or originators and do not necessarily reflect the views of the National Science Foundation.

Bibliographic Notes

ICSI Technical Report TR-12-002.

Abbreviated Authors

T. Callahan, M. Allman, and M. Rabinovich

ICSI Research Group

Networking and Security

ICSI Publication Type

Technical Report