Home // International Journal On Advances in Systems and Measurements, volume 5, numbers 1 and 2, 2012 // View article
Authors:
Stefan Rass
Sandra Koenig
Keywords: Quantum Cryptography, Markov-Chain, Secure Routing, Information-Theoretic Security
Abstract:
Quantum networks are communication networks in which adjacent nodes enjoy perfectly secure channels thanks to quantum key distribution (QKD). While QKD is renowned for perfect point-to-point security and its eavesdropping detection capabilities, end-to-end security is nontrivial to achieve. More importantly, the eavesdropping detection can indeed be turned against the system itself. It is known that perfect end-to-end security can be created from point-to-point security by means of multipath transmission (in fact, there is no other way to do this, assuming no pre-shared secrets and avoiding public-key cryptography). However, multipath transmission requires node-disjoint paths, which in turn are to be assured by the underlying routing protocol. At this point, an active or passive adversary may intentionally eavesdrop on the QKD protocol to temporarily cut a channel and to cause key-buffers running empty and enforcing local rerouting of packets towards nodes under his control. Consequently, the multipath transmission channels might no longer be non-intersecting, thus defeating the overall security by exploiting QKD's eavesdropping detection facilities. Alternatively, an active adversary may as well insert bogus traffic to cause local congestion, thus even sparing the effort of eavesdropping on a QKD link. In this work, we use Markov chains to model a multipath transmission, and we discuss the extent to which secure multipath transmission is resilient against local congestions caused by an adversary. We argue that a protection against an active adversary who uses bogus traffic to fiddle with the routing, calls for additional security measures, perhaps even beyond the capabilities of QKD or multipath transmission. It turns out that robustness against passive and active adversaries can be retained as long as no bogus traffic is observed.
Pages: 22 to 33
Copyright: Copyright (c) to authors, 2012. Used with permission.
Publication date: June 30, 2012
Published in: journal
ISSN: 1942-261x