General individual attack on the ping-pong protocol with completely entangled pairs of qutrits

TL;DR

This paper analyzes the security of the ping-pong quantum communication protocol using entangled qutrits, deriving eavesdropper information bounds and comparing security levels with qubit-based protocols.

Contribution

It provides a detailed analysis of individual attacks on qutrit-based ping-pong protocol and compares its security to qubit-based protocols, highlighting the need for security amplification.

Findings

Qutrit-based ping-pong protocol has higher security than qubit-based.

Security is only asymptotic with current control methods.

Additional security measures are needed for practical use.

Abstract

The general individual (non-coherent) attack on the ping-pong protocol with completely entangled pairs of three-dimensional quantum systems (qutrits) is analyzed. The expression for amount of the eavesdropper's information as functions from probability of attack detection is derived. It is shown, that the security of the ping-pong protocol with pairs of qutrits is higher the security of the protocol with pairs of qubits. It is also shown, that with the use by legitimate users in a control mode two mutually unbiased measuring bases the ping-pong protocol with pairs of qutrits, similar to the protocol with groups of qubits, possesses only asymptotic security and requires additional methods for its security amplification.