Abstract: Quantum networks promise unparalleled security by leveraging
entanglement-based protocols and trusted quantum repeaters to enable appli-
cations such as quantum key distribution and distributed quantum computing.
However, as these networks evolve in complexity, they expose new operational
and control vulnerabilities that can be exploited by adversaries. Among these
vulnerabilities, subtle attacks on the entanglement swapping process and ma-
nipulating performance metrics pose significant challenges to network integrity
and efficiency. This study delves into a relatively unexplored class of threats: the
Black Hole Repeater attacks. These attacks involve malicious nodes deliberately
introducing errors or falsifying metrics that undermine the success rate of quan-
tum operations and lead to resource inefficiencies while remaining undetectable
by traditional monitoring techniques such as quantum tomography. Through si-
mulations in diverse network topologies, we demonstrate the potential impact
of these attacks on key performance metrics, underscoring the need for adap-
tive monitoring solutions and resilient architectures to enhance the security of
quantum networks.