Deterministic Random Number Generator Attack Against the Kirchhoff-Law-Johnson-Noise Secure Key Exchange Protocol Academic Article uri icon


  • This paper demonstrates the vulnerability of the Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchanger to compromised random number generator(s) even if these random numbers are used solely to generate the noises emulating the Johnson noise of Alices and Bobs resistors. The attacks shown are deterministic in the sense that Eves knowledge of Alices and/or Bobs random numbers is basically deterministic. Moreover, no statistical evaluation is needed, except for rarely occurring events of negligible, random waiting time and verification time. We explore two situations. In the first case, Eve knows both Alices and Bobs random noises. We show that, in this situation, Eve can quickly crack the secure key bit by using Ohms Law. In the other situation, Eve knows only Bobs random noise. Then Eve first can learn Bobs resistance value by using Ohms Law. Therefore, she will have the same knowledge as Bob, thus at the end of the bit exchange period, she will know Alices bit.

published proceedings


author list (cited authors)

  • Chamon, C., Ferdous, S., & Kish, L. B.

citation count

  • 5

complete list of authors

  • Chamon, Christiana||Ferdous, Shahriar||Kish, Laszlo B

publication date

  • December 2021