Vulnerability of the Key Sharing Protocol Executing over the Noiseless Public Channels with Feedback

Abstract

It has been proven that several recently published protocols for exchanging keys over noiseless channels by the same authors as in the current paper have real vulnerability to eavesdropping rooted in the attacker’s receiver optimization procedure. Moreover, we have proved that protocols of exchanging by binary bits and by real-valued numbers have zero secret capacity and hence nothing perspectives in their applications. Protocols of exchanging by real-valued vectors and matrices have nonzero secret capacity under the condition of hard decoding by eavesdroppers. The use of optimal soft decoding results in a compromise of such protocols. Thus, a problem is still open about an existence or not-existence of key sharing protocols executed over noiseless public channels.

Keywords

• key sharing. cryptography. security. information security
• wire-tap channel