Quantum Computing: Post-Quantum Cybersecurity

Understanding Quantum Computing and Its Security Implications

Traditional computers operate using bits—binary digits represented as either 0 or 1. Quantum computers, however, leverage quantum bits or "qubits" that can exist in multiple states simultaneously due to the principles of quantum mechanics. This property, called superposition, combined with quantum entanglement, allows quantum computers to process enormous amounts of data in parallel.

While general-purpose quantum computers with thousands of stable qubits remain years away, specialized quantum systems with 50-100 qubits already exist, and significant advancements continue at an accelerating pace. Organizations like IBM, Google, and various national research institutions are making substantial investments in quantum development.

Which Encryption Standards Are at Risk?

The security concern stems from quantum algorithms, particularly Shor's algorithm, which can efficiently factor large numbers—the mathematical problem underpinning widely used public-key cryptography systems. When implemented on sufficiently powerful quantum computers, these algorithms will break:

• RSA Encryption: The foundation of secure communications across the internet
• Elliptic Curve Cryptography (ECC): Used in many modern systems for key exchange
• Diffie-Hellman Key Exchange: Critical for establishing secure connections

"The question isn't whether quantum computers will break current encryption, but when. Organizations that handle data with long-term sensitivity need to begin migrating to quantum-resistant standards today." — Michael Chen, Chief Security Architect

The Quantum Timeline: How Soon Should We Worry?

Experts disagree on exact timelines, but most security professionals suggest that practical quantum computers capable of breaking current encryption will emerge within 5-15 years. This creates a "harvest now, decrypt later" threat: adversaries can collect encrypted data today with the expectation of decrypting it once quantum computing matures.

This is particularly concerning for data with long-term sensitivity, such as:

• Healthcare records with lifetime relevance
• Intellectual property with decades-long value
• National security information
• Financial and infrastructure systems

Post-Quantum Cryptography: The New Frontier

The cryptographic community has been developing quantum-resistant algorithms for over a decade. In 2016, the National Institute of Standards and Technology (NIST) initiated a process to standardize post-quantum cryptography (PQC) algorithms that can withstand quantum attacks.

After years of rigorous analysis, NIST has selected several promising candidates based on mathematical problems believed to be difficult even for quantum computers:

NIST Selected PQC Algorithms

• CRYSTALS-Kyber: For key establishment, based on structured lattice problems
• CRYSTALS-Dilithium, FALCON, and SPHINCS+: For digital signatures, based on different mathematical approaches

These algorithms provide alternatives to vulnerable public-key systems, but they come with tradeoffs in terms of key size, performance, and implementation complexity.

Hybrid Cryptographic Approaches

While transitioning to quantum-resistant algorithms, many organizations are adopting hybrid approaches that combine traditional and post-quantum cryptography. This strategy provides protection against both conventional and quantum adversaries during the migration period.

For example, a TLS connection might use both an RSA key exchange and a CRYSTALS-Kyber key exchange, requiring an attacker to break both to compromise the connection.

Preparing Your Organization for the Quantum Era

Organizations should begin preparing for quantum threats through a structured approach that balances immediate security needs with long-term quantum resilience. Here's a practical roadmap:

1. Conduct a Cryptographic Inventory and Risk Assessment

The first step is understanding where and how cryptography is used across your environment:

• Identify Cryptographic Assets: Catalog all systems using cryptography, including VPNs, identity systems, digital signatures, and certificate authorities
• Assess Data Longevity Requirements: Determine how long different types of data need to remain secure
• Evaluate Third-Party Dependencies: Assess vendors, cloud providers, and other partners for their quantum readiness
• Prioritize Systems: Focus resources on the most critical systems and those with long-term data protection requirements

Many organizations are surprised by the cryptographic complexity revealed during this process, often discovering encryption in unexpected places throughout their infrastructure and applications.

2. Develop Cryptographic Agility

Cryptographic agility—the ability to rapidly transition between cryptographic algorithms without major system redesign—is crucial for quantum preparedness:

• Abstract Cryptographic Implementations: Design systems with cryptographic modularity that separates algorithm implementation from application logic
• Document Cryptographic Dependencies: Maintain comprehensive documentation of all cryptographic libraries and their usage
• Establish Update Processes: Create streamlined procedures for deploying cryptographic updates across the organization
• Test Transition Strategies: Conduct tabletop exercises and technical tests of algorithm migration in non-production environments

Organizations with legacy systems face particular challenges, as these often have tightly coupled cryptographic implementations that resist easy updates.

3. Education and Monitoring

• Stay Informed: Monitor developments in quantum computing and post-quantum cryptography through resources like the NIST Post-Quantum Cryptography Standardization project
• Educate Decision Makers: Ensure leadership understands the quantum threat timeline and resource requirements for transition
• Train Technical Teams: Develop internal expertise in post-quantum cryptography implementation
• Engage with Standards Bodies: Participate in industry groups focused on quantum readiness

4. Practical Implementation Steps

While full transition to post-quantum cryptography may take years, organizations can take concrete actions today:

1. Increase Key Sizes for Symmetric Encryption: Transition from AES-128 to AES-256, which provides significant protection against quantum attacks
2. Implement Quantum-Safe Key Exchange in Critical Systems: Begin testing post-quantum algorithms in parallel with existing methods
3. Adopt Hybrid Certificates: Work with certificate authorities supporting hybrid classical/post-quantum certificates
4. Update Cryptographic Libraries: Ensure cryptographic libraries are maintained and capable of supporting algorithm transitions
5. Plan for Increased Resource Requirements: Many post-quantum algorithms require larger keys and more computational resources

Case Study: Post-Quantum Migration in Financial Services

A regional financial institution with long-term data protection requirements approached Borealis Security for assistance with their quantum readiness strategy. They were particularly concerned about transaction records and customer financial data that requires protection for decades.

Our approach included:

• Comprehensive Inventory: We identified over 200 cryptographic implementations across their core banking platforms, customer portals, and internal applications
• Risk Assessment: We categorized systems by quantum vulnerability and data sensitivity, prioritizing client authentication systems and long-term data storage
• Migration Strategy: We developed a three-phase approach:
  1. Immediate enhancement of symmetric key sizes
  2. Implementation of hybrid cryptography for external communications
  3. Phased transition to fully quantum-resistant algorithms over 24 months
• Vendor Assessment: We evaluated the quantum readiness of key technology vendors and developed contingency plans for those without clear roadmaps

The institution has now completed the first phase of their migration and reports greater confidence in their long-term security posture, along with improved cryptographic governance processes that benefit their overall security program.

The Regulatory Landscape

Governments and regulatory bodies are increasingly focused on quantum threats, with several significant developments:

• U.S. National Security Memorandum 10: Directs federal agencies to begin transitioning to quantum-resistant cryptography
• European Telecommunications Standards Institute (ETSI): Published guidelines for quantum-safe cryptography implementation
• Financial Industry: Organizations like the Financial Industry Regulatory Authority (FINRA) have issued guidance on quantum preparedness
• Healthcare: Emerging discussions around HIPAA implications of quantum computing threats to protected health information

Forward-thinking organizations are treating quantum readiness as part of their overall regulatory compliance strategy, anticipating more stringent requirements as the technology matures.

Beyond Encryption: Quantum Detection and Networking

While much focus remains on post-quantum cryptography, quantum technology offers potential cybersecurity benefits as well:

Quantum Random Number Generation (QRNG)

Truly random numbers are essential for strong cryptography but difficult to generate using classical computing methods. Quantum random number generators leverage quantum effects to produce provably random values, enhancing encryption strength and unpredictability.

Quantum Key Distribution (QKD)

QKD uses principles of quantum mechanics to securely distribute encryption keys. Unlike algorithmic approaches, QKD's security derives from fundamental physics—specifically the fact that measuring a quantum system disturbs it detectably.

While promising, QKD has significant limitations including range, infrastructure requirements, and vulnerability to certain types of attacks. Most security experts recommend focusing on post-quantum cryptography as the primary quantum defense strategy, with QKD as a potential supplementary technology for specific high-security applications.

Conclusion: Balancing Urgency and Practicality

Quantum computing's impact on cybersecurity represents a slow-moving but inevitable transformation. Organizations face the challenge of balancing appropriate urgency against practical resource limitations and competing priorities.

The key principles for successful navigation of this transition include:

• Start Now, Move Deliberately: Begin assessment and planning immediately, but implement changes methodically
• Prioritize Based on Risk: Focus first on systems protecting high-value, long-term sensitive data
• Build Cryptographic Governance: Establish processes that will support ongoing cryptographic evolution
• Leverage Standards: Align with emerging standards rather than implementing customized solutions
• Address the Full Stack: Consider hardware, software, people, and processes in your quantum readiness strategy

At Borealis Security, we believe quantum readiness represents not just a technical challenge but an opportunity to strengthen overall security posture. Organizations that approach quantum readiness strategically often discover broader benefits in cryptographic governance, inventory management, and security architecture.

The future of cryptography will be shaped by quantum computing, but with proper preparation, organizations can ensure their security keeps pace with both technological advancement and emerging threats.