Theoretical and Applied Informatics
Security of the quantum direct communication based on pairs of completely entangled qudits
Piotr Zawadzki
Abstract
Quantum secure direct communication protocols offer confidential transmission of classic information over the quantum channel without a prior key agreement. The ping-pong based protocols provide asymptotic security and detailed analysis of the security level provided by each variant of the protocol is required. The paper presents a general method of calculation of the eavesdropped information as a function of the attack detection probability. The method is applied to the ping-pong protocol based on completely entangled pairs of qudits. The lower and upper bound on the amount of the leaked information is provided.