AC Loop Current Attacks Against The KLJN Secure Key Exchange Scheme
This work addresses a vulnerability in a specific secure communication protocol, which is incremental as it builds on prior attacks like DC ground loop methods.
The authors tackled the security of the KLJN key exchange scheme by introducing a new attack exploiting parasitic AC voltage sources from ground loops and EMI, demonstrating it in low and high-frequency cases and discussing defense protocols.
A new attack against the Kirchhoff-Law-Johnson-Noise(KLJN) secure key exchange scheme is introduced. The attack exploits a parasitic (periodic) AC voltage-source at either Alice or Bob ends. Such situations exist due to AC ground loops and electromagnetic interference (EMI). In the low-frequency case, the procedure is the generalized form of the former DC ground loop based attack. In the high-frequency case, the power spectrum of the wire voltage is utilized. The attack is demonstrated in both the low and the high-frequency situations. Defense protocols against the attack are also discussed.