From 9a4475457bf834bef4095bf74c2c43e33a40f1b8 Mon Sep 17 00:00:00 2001 From: jaseg Date: Wed, 26 Jun 2024 13:33:35 +0200 Subject: [PATCH] QKD WIP --- chapter-qkd/chapter.tex | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/chapter-qkd/chapter.tex b/chapter-qkd/chapter.tex index 3d83310..2de44eb 100644 --- a/chapter-qkd/chapter.tex +++ b/chapter-qkd/chapter.tex @@ -167,6 +167,33 @@ improvement in today's hardware. \section{Securing QKD Networks with Inertial HSMs} +As we discussed above, when it comes down to practical, end-to-end security properties, Quantum Key Distribution +removes trust in the hardness of particular mathematical problems (good!), but increases trust in the physical +integrity of the transceivers of the QKD link (bad!). In scenarios where the communicating parties are all located +within physical proximity, in QKD meaning within at most a few hundred kilometers from each other depending on secret +key rate requirements, this added trust is of no consequence because the communcating parties' hardware must be trusted +in either QKD-assisted or purely classical setups. However, this trust requirement becomes a burden as soon as at least +one party is too far away (or higher secret key rates are required), as now physically trusted relays become necessary. + +Extrapolating to practical deployments, we can make two predictions. First, as QKD only solves key distribution, but the +actual data transfer still happens through normal off-the-shelf telecommunications components in QKD networks, there is +no reason for a practical QKD setup to \emph{not} also use classical cryptography as an additional layer for defense in +depth, +% FIXME citation on defense in depth, and on this hybrid scenario +meaning the QKD setup will at worst degrade to the same security a purely classical system would provide, never less. + +The second prediction we can make is that any practical QKD network will have to use trusted relays to bridge large +distances. While in certain specialized applications such as the proposed financial QKD network in Swizerland +% FIXME citation +smaller, isolated networks are conceivable, in every telecommunication system from the telegraph through the telephone +system and up to the internet it has been shown conclusively that there is a real demand for a unified, global +interconnected network. % FIXME citation on historic networks + +In this section, we will outline a solution that provides practical, end-to-end security in large-scale QKD networks by +delegating the hardware trust issue of QKD relays to Inertial Hardware Security Modules. The primary design challenges +we will address are the systems' overall envelope design, optical passthroughs, and matching the cryptographic +assumptions behind the IHSM's heartbeat and alarm subsystem to those of the QKD application. + \section{Outlook} \newpage