Publication Details

Title: Psst, Over Here: Communicating Without Fixed Infrastructure
Author: T. Callahan, M. Allman, and M. Rabinovich
Bibliographic Information: ICSI Technical Report TR-12-002. Also presented at the 31st International Conference on Computer Communications (INFOCOM 2012) Mini-Conference, Orlando, Florida, March 2012.
Date: January 2012
Research Area: Networking and Security
Type: Technical Reports
PDF: http://www.icsi.berkeley.edu/pubs/techreports/TR-12-002.pdf

Overview:
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.

Acknowledgements:
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 Reference:
T. Callahan, M. Allman, and M. Rabinovich. Psst, Over Here: Communicating Without Fixed Infrastructure. ICSI Technical Report TR-12-002. Also presented at the 31st International Conference on Computer Communications (INFOCOM 2012) Mini-Conference, Orlando, Florida, March 2012., January 2012