Quantum Computing and Post-Quantum Cryptography

Abstract / Overview:

Quantum computing promises immense computational power that could break many of today’s cryptographic systems — particularly those based on RSA, ECC, and DH. As this future approaches, the cybersecurity world is preparing through Post-Quantum Cryptography (PQC), developing new encryption methods that are resistant to quantum attacks. This topic explores how quantum computing threatens modern encryption, the development of quantum-safe algorithms, and the global race to adopt PQC before it’s too late.

Key Sections / Talking Points:

🧠 1. Quantum Computing 101

What makes quantum computers different?
Uses qubits instead of bits, enabling superposition and entanglement.
Why it matters to crypto:
Algorithms like Shor’s Algorithm can factor large primes exponentially faster, breaking RSA and ECC.

🔓 2. How Quantum Computing Breaks Modern Cryptography

RSA (Rivest–Shamir–Adleman)
Vulnerable due to quantum factoring.
Elliptic Curve Cryptography (ECC)
Broken via Shor’s algorithm as well.
Diffie–Hellman Key Exchange
Also at risk due to efficient discrete log solving by quantum algorithms.

🛡️ 3. Post-Quantum Cryptography (PQC)

Definition: Cryptographic algorithms that are believed to be secure against both quantum and classical computers.
Main types of PQC approaches:
- Lattice-based cryptography (e.g., Kyber, Dilithium)
- Code-based cryptography
- Multivariate polynomial cryptography
- Hash-based cryptography

🌐 4. NIST’s Post-Quantum Cryptography Standardization

Global initiative to standardize quantum-resistant algorithms.
Finalists (2022):
- Kyber (encryption/key encapsulation)
- Dilithium (digital signatures)
- Falcon and SPHINCS+ also recognized.
Expected adoption timeline: Official standards being finalized and adopted in stages through 2025–2030.

🏦 5. Industries Most at Risk

Banking & finance
Government / military
Cloud and telecom providers
Healthcare (long-term confidentiality needs)
Data encrypted today may be harvested and decrypted years later — a threat known as “Harvest Now, Decrypt Later”.

🔄 6. Migration Challenges

Legacy systems: Upgrading cryptography in critical infrastructure is hard and slow.
Algorithm interoperability: Hybrid solutions are being used in the meantime (e.g., PQC + RSA).
Performance overhead: Many PQC algorithms require more bandwidth and computational resources.

⚖️ 7. Ethical, Legal, and Geopolitical Implications

Quantum supremacy race: U.S., China, EU all investing billions.
Export restrictions: Quantum tech and PQC tools may become regulated.
Digital sovereignty concerns over who controls quantum-safe standards.

🔮 8. Future Trends

Development of quantum-resistant blockchain algorithms.
Integrating PQC into IoT and 5G/6G infrastructure.
The potential rise of Quantum Key Distribution (QKD) in combination with classical PQC.

📚 Suggested Tools & Reading

NIST PQC Project: csrc.nist.gov
IBM Quantum, Google Sycamore
Papers:
- "Quantum Computing and RSA Cryptography" – ACM
- "Post-Quantum Cryptography: Current State and Challenges" – IEEE