Quantum Technologies and Post-Quantum Security for Critical Infrastructures

Dear Colleagues,

Scope and Motivation

Critical infrastructures underpin modern society, encompassing energy systems, transportation networks, healthcare, financial services, water management, telecommunications, public administration, industrial systems, and, increasingly, space-based infrastructures such as satellite communications, navigation, and Earth observation. The resilience and security of these interconnected systems are essential to economic stability, public safety, and national sovereignty.

The emergence of quantum technologies introduces both transformative opportunities and significant security challenges. On one hand, quantum computing threatens widely deployed cryptographic schemes, necessitating the transition toward post-quantum cryptography (PQC). On the other hand, quantum technologies such as quantum communication, quantum sensing, and quantum timing offer new capabilities for securing and monitoring critical infrastructures.

At the same time, the rapid evolution of artificial intelligence (AI), particularly large language models (LLMs) and autonomous agents, is reshaping the threat landscape. AI enables highly automated, adaptive, and scalable cyberattacks, including advanced reconnaissance, vulnerability discovery, and coordinated exploitation. Consequently, future critical infrastructures must be resilient not only to quantum-enabled cryptographic disruption, but also to AI-enhanced adversarial capabilities.

This Special Issue aims to explore the convergence of quantum technologies, post-quantum security, and AI-driven cybersecurity, addressing the dual challenge of long-term cryptographic resilience and immediate intelligent threats. Contributions that bridge theory and practice, and that demonstrate applicability to real-world infrastructure systems, are particularly encouraged.

Topics of Interest

This Special Issue invites high-quality submissions including original research articles, reviews, and case studies on topics including, but not limited to, the following:

1. Post-Quantum Security and Cryptographic Migration

• Post-Quantum Cryptography (PQC) Migration for Critical Infrastructures: Crypto-agility, hybrid cryptographic schemes, migration roadmaps, and risk assessment for long-lived and safety-critical systems.
• Quantum-Secure Architectures for Cyber-Physical and Industrial Systems: Security mechanisms for SCADA, ICS/OT, smart grids, transportation systems, and industrial IoT.
• Lightweight PQC for Embedded and Resource-Constrained Systems: Efficient implementations for IoT, edge devices, and satellite platforms.

2. Quantum Communication, Sensing and Space Technologies

• Quantum Key Distribution (QKD) and Secure Communication Networks: Protocols, architectures, and integration of quantum communication technologies into critical infrastructure networks.
• Space-Based Quantum Communications and Infrastructure Security: Satellite-based QKD, secure space–ground links, and protection of space assets supporting critical services.
• Quantum Sensing and Monitoring for Infrastructure Resilience: Applications in geohazard detection, structural health monitoring, environmental sensing, and energy systems.
• Quantum Timing and Resilient Positioning, Navigation, and Timing (PNT): High-precision synchronization and navigation resilience in adversarial or degraded environments.

3. The AI-Quantum Threat Nexus and Intelligent Defense

• AI-Enhanced Threats to Quantum-Secure Infrastructures: Use of AI, LLMs, and autonomous agents for automated cyberattacks, vulnerability discovery, and adaptive exploitation of newly deployed PQC systems.
• Adversarial Machine Learning in Post-Quantum Infrastructure Protection: Robustness of AI-based security systems operating in quantum-resilient networks against evasion, poisoning, and model extraction attacks.
• AI for Autonomous Cyber Defense and Crypto-Agility Operations: Intelligent agents for monitoring, incident response, and orchestrating adaptive cryptographic defense with human-in-the-loop control.
• Secure Deployment of LLMs and AI Agents in Quantum-Secured Environments: Architectures addressing prompt injection, hallucination risks, data leakage, and privilege escalation within post-quantum operational domains.
• Trustworthy, Explainable, and Compliant AI for Quantum-Secure Systems: Transparency, auditability, and regulatory alignment of AI models deployed in safety-critical, quantum-resilient infrastructures.

4. Systems Engineering, Simulation and Deployment

• Digital Twins and Simulation for Quantum-Secure Infrastructure: Modeling, testing, and validation of cryptographic transition strategies using digital twins and simulation environments.
• Supply Chain Security for Quantum and Post-Quantum Technologies: Trust, verification, and lifecycle security of quantum hardware and post-quantum software components.
• Sector-Specific Case Studies and Deployments: Applications in energy, transport, healthcare, finance, water, telecommunications, manufacturing, public administration, and space systems.

Dr. Alexandru Stanciu
Dr. Rui Araújo
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• quantum computing
• quantum communication
• quantum sensing
• quantum timing
• quantum key distribution (QKD)
• space-based quantum communications
• post-quantum cryptography (PQC)
• PQC migration
• crypto-agility
• hybrid cryptographic schemes
• quantum-secure architectures
• quantum-resilient networks
• quantum-secured environments
• critical infrastructures
• cyber-physical systems
• digital twins
• large language models (LLMs)
• autonomous agents