Modern Cryptography Part II: The Quantum Computing Threat

Quantum computers pose an existential threat to the cryptographic foundations of internet security. Understanding this threat is essential for long-term security planning.

The Quantum Threat Landscape

What's at Risk

Current encryption relies on mathematical problems that classical computers can't solve efficiently:

| Algorithm | Use Case | Quantum Vulnerable? | |-----------|----------|---------------------| | RSA-2048 | TLS, Code Signing | ✅ Yes (Shor's Algorithm) | | ECDSA | Bitcoin, TLS | ✅ Yes (Shor's Algorithm) | | AES-256 | Data Encryption | ⚠️ Reduced (Grover's Algorithm) | | SHA-256 | Hashing | ⚠️ Reduced (Grover's Algorithm) |

Timeline Estimates

• 2025-2030: "Harvest now, decrypt later" attacks accelerate
• 2030-2035: Cryptographically relevant quantum computers possible
• 2035+: Widespread quantum capability

"Harvest Now, Decrypt Later"

Nation-state actors are already:

1. Intercepting encrypted traffic
2. Storing it in data centers
3. Waiting for quantum computers to decrypt

Data with long-term sensitivity (medical records, state secrets, financial data) is already at risk.

Post-Quantum Cryptography (PQC)

NIST Standardized Algorithms

NIST has selected quantum-resistant algorithms:

• ML-KEM (CRYSTALS-Kyber): Key encapsulation
• ML-DSA (CRYSTALS-Dilithium): Digital signatures
• SLH-DSA (SPHINCS+): Stateless hash-based signatures

Migration Challenges

Organizations face significant hurdles:

• Embedded systems with limited update capabilities
• Legacy applications with hardcoded cryptography
• Certificate infrastructure dependencies
• Performance overhead of PQC algorithms

Preparing Your Organization

Immediate Actions

1. Inventory Cryptographic Usage: Document where and how encryption is used
2. Classify Data Sensitivity: Identify data requiring long-term confidentiality
3. Test PQC Libraries: Evaluate OpenSSL 3.2+, liboqs
4. Plan Migration: Develop a multi-year transition roadmap

Testing with RaptorX

RaptorX's security assessments include:

• Cryptographic algorithm inventory
• Weak cipher detection
• Certificate chain analysis
• Recommendations for quantum-safe alternatives

Code Example: Hybrid Key Exchange

# Using hybrid approach: Classical + PQC
from cryptography.hazmat.primitives.asymmetric import x25519
from oqs import KeyEncapsulation

# Classical key exchange
classical_private = x25519.X25519PrivateKey.generate()
classical_public = classical_private.public_key()

# Post-quantum key exchange
pqc = KeyEncapsulation("Kyber768")
pqc_public = pqc.generate_keypair()

# Combined key = Classical || PQC
# Secure even if one scheme is broken

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The quantum transition will be the largest cryptographic migration in history. RaptorX helps organizations identify their quantum exposure and plan accordingly.

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