  The proliferation of mobile networks and their increasing importance to
modern life, combined with the emerging threat of quantum computing, present
new challenges and opportunities for cybersecurity. This paper addresses the
complexity of protecting these critical infrastructures against future quantum
attacks while considering operational sustainability. We begin with an overview
of the current landscape, identify the main vulnerabilities in mobile networks,
and evaluate existing security solutions with new post-quantum cryptography
(PQC) methods. We then present a quantum-secure architecture with PQC and
Quantum Key Distribution (QKD) tailored explicitly for sustainable mobile
networks and illustrate its applicability with several use cases that emphasize
the need for advanced protection measures in this new era. In addition, a
comprehensive analysis of PQC algorithm families is presented, focusing on
their suitability for integration in mobile environments, with particular
attention to the trade-offs between energy consumption and security
improvements. Finally, recommendations for strengthening mobile networks
against quantum threats are provided through a detailed examination of current
challenges and opportunities.
