Optimization of the Key Sharing Protocol for Noiseless Public Channels without the Use of Cryptographic Assumptions

Traditional physical-layer based secret key sharing scheme typically suggests some cryptographic assumption. In this paper we develop the key sharing protocol for noiseless public channels without any cryptographic assumptions that was proposed recently by the same group of authors. But in contrast to our previous investigations we introduce here more profound research of previous approach. First of all we replace four-step protocol presented before to two-step protocol without loss of key security. A comparison of protocol with and without additional sub key channel is given. Impossibility to use integers instead of matrices in execution of information exchange over the channel is demonstrated. Selecting of the main key sharing protocol parameters in order to minimize channel traffic, given the key bit reliability and information-theoretic security is provided. As a source of random date that are needed for a creation of matrices is tested a compact hardware device generating of truly random sequences. It follows from our investigations that the proposed key sharing protocol can be easily executed by individuals involved into ordinary Internet activity providing information theoretical security level even during post quantum period.