Error Elimination in the KLJN Secure Key Exchange and Vehicular Applications

The Kirchhoff-law-Johnson-noise (KLJN) system is a classical physical secure key exchange scheme based on the Kirchhoff’s circuit loop law and the fluctuation-dissipation theorem of statistical physics. This dissertation contains two main studies related to this scheme: bit error analysis and removal, and applications in vehicular communication systems. The thesis starts with a presentation of some of the challenges faced by modern communications. It also includes a description of the working principle of the KLJN system and the motivation upon which this dissertation is built. Then, a study of the errors in this scheme is carried out. In the first part, the types of errors due to statistical inaccuracies in the voltage-based and current-based measurement modes are classified and analyzed. In both measurement modes and for all types of errors, at fixed bandwidth, the error probabilities decay exponentially versus the duration of the bit sharing period. In the second part, an error removal method is proposed to improve the fidelity of the system. This method is based on the combination of the voltage-based and current-based schemes and it drastically reduces the error probabilities. The second topic of study in the thesis explores a potential practical application for the KLJN key exchange scheme. First, we present a vehicular communication network architecture with unconditionally secure KLJN keys. Secondly, a new solution for secure KLJN key donation to vehicles is proposed and an upper limit for the lifetime of this key is given. A summary of the work is given in the last section and the main results of the research are discussed. These contributions include: closed-form expressions for the error probabilities in the KLJN system, error removal methods without the need of implementing any error correcting technique, and a new potential vehicular application for the KLJN scheme. Some of the future research initiatives related to these topics are discussed

Current and voltage based bit errors and their combined mitigation for the Kirchhoff-law-Johnson-noise secure key exchange

We classify and analyze bit errors in the current measurement mode of the Kirchhoff-law-Johnson-noise (KLJN) key distribution. The error probability decays exponentially with increasing bit exchange period and fixed bandwidth, which is similar to the error probability decay in the voltage measurement mode. We also analyze the combination of voltage and current modes for error removal. In this combination method, the error probability is still an exponential function that decays with the duration of the bit exchange period, but it has superior fidelity to the former schemes.Comment: 9 pages, accepted for publication in Journal of Computational Electronic

Cable Capacitance Attack against the KLJN Secure Key Exchange

The security of the Kirchhoff-law-Johnson-(like)-noise (KLJN) key exchange system is based on the Fluctuation-Dissipation-Theorem of classical statistical physics. Similarly to quantum key distribution, in practical situations, due to the non-idealities of the building elements, there is a small information leak, which can be mitigated by privacy amplification or other techniques so that the unconditional (information theoretic) security is preserved. In this paper, the industrial cable and circuit simulator LTSPICE is used to validate the information leak due to one of the non-idealities in KLJN, the parasitic (cable) capacitance. Simulation results show that privacy amplification and/or capacitor killer (capacitance compensation) arrangements can effectively eliminate the leak.Comment: Accepted for publication in the journal: Informatio

Design of a system to support the mobility of visually impaired people

The autonomous mobility for visually impaired people has been an issue in where several researchers have contributed with proposals in order to solve it. However, there is a lot of work to carry out in the cities in where this kind of technology has been applied, but also in other cities or town where this or other technology not has arrived yet. In this work two different ICT-based systems have been described, which provide helps in the mobility of visually impaired people in the public transport in Panama. One of them consists of the development of new applications for Android-based smartphones, and the second system is based on the development of RF modules into the ISM radio band. These prototypes are used by the visually impaired people and by the bus driver, and one of them is installed at the bus stop

Errors and their mitigation at the Kirchhoff-law-Johnson-noise secure key exchange

A method to quantify the error probability at the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange is introduced. The types of errors due to statistical inaccuracies in noise voltage measurements are classified and the error probability is calculated. The results are demonstrated with practical considerations