Transient attack on Kish Key Distribution (KKD)
Channel: UniAdel
Date: 28/05/2015

The Kish key distribution (KKD) system has been proposed as a classical alternative to quantum key distribution, making use of temperature-matched thermal noise. Previous analyses assume instant propagation of signals along the line connecting the two users. We describe an attack that takes advantage of propagation delays. At the start of each bit period, the noise temperature will then be increased from zero to its final value.

During this process, the temperature variation will take time to propagate along the line, resulting in a temperature mismatch. We analyze the information leak due to this effect and consider several potential mitigation schemes.