Quantum network security dependent on connection density between trusted nodes

TL;DR

This paper analyzes how increasing connection density between trusted nodes in a quantum network impacts its security, providing formulas for failure probability and trade-offs for network design and optimization.

Contribution

It introduces a model quantifying the effect of connection density on quantum network security and derives failure probability expressions for different network configurations.

Findings

Failure probability expressions depend on connection density and number of nodes.

Trade-off identified between security enhancement and resource expenditure.

Results aid in designing and optimizing quantum networks.

Abstract

In this paper we estimate how introduction of additional connections between trusted nodes through one, two and so on (i.e. connection density) to a quantum network with serial connection of trusted nodes affects its security. We provide proper scaling of failure probability of authentication and quantum key distribution protocols to the level of the whole quantum network. Expressions of the failure probability dependent on the total number of connected nodes between users and connection density for given mean failure probability of each element are derived. The result provides explicit trade-off between increase of the key transport security and consequent increase of spent resources. We believe that obtained result may be useful for both design of future network and optimization of existing ones.