Quantum-Safe Cryptography: Preparing for Post-Quantum Security 2026

# Using liboqs (Open Quantum Safe)
from liboqs import KEM

# Select ML-KEM (Kyber) algorithm
kem = KEM("Kyber512")

# Generate key pair
public_key = kem.generate_keypair()
secret_key = kem.export_secret_key()

# Encapsulate (like encryption)
ciphertext, shared_secret_enc = kem.encaps(public_key)

# Decapsulate (like decryption)
shared_secret_dec = kem.decaps(secret_key, ciphertext)

# Both sides now have the same shared secret
assert shared_secret_enc == shared_secret_dec

from liboqs import Signature

# Select ML-DSA (Dilithium) algorithm
sig = Signature("Dilithium2")

# Generate key pair
public_key = sig.generate_keypair()
secret_key = sig.export_secret_key()

# Sign a message
message = b"Important data that needs authentication"
signature = sig.sign(message, secret_key)

# Verify signature
is_valid = sig.verify(message, signature, public_key)

print(f"Signature valid: {is_valid}")

# Combine classical and post-quantum algorithms
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import rsa, padding
from cryptography.hazmat.primitives import serialization
import liboqs

class HybridEncryptor:
    def __init__(self):
        self.kem = liboqs.KEM("Kyber512")
        self.rsa = rsa.generate_private_key(
            public_exponent=65537,
            key_size=2048
        )
    
    def hybrid_encrypt(self, plaintext: bytes) -> bytes:
        # Generate QKD key
        pk = self.kem.generate_keypair()
        ct, qkd_secret = self.kem.encaps(pk)
        
        # Generate classical key
        classical_key = rsa.generate_private_key(
            public_exponent=65537, 
            key_size=2048
        )
        
        # Encrypt with both
        # ... combine both ciphertexts
        return combined_ciphertext
    
    def hybrid_decrypt(self, ciphertext: bytes) -> bytes:
        # Decrypt using both algorithms
        # ... combine both plaintexts
        return plaintext

# OpenSSL configuration for post-quantum TLS
openssl_conf: |
    # Hybrid cipher suites
    CipherString = ECDHE-ML-KEM-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384
    
    # Provider configuration
    [provider_sect]
    default = default_sect
    oqs = oqs_sect
    
    [oqs_sect]
    activate = 1
    algorithm_slh_dsa = SLH-DSA-SHA2-128s
    algorithm_ml_kem = ML-KEM-512

# Scan for vulnerable cryptography
import subprocess
import re

class CryptoInventory:
    def scan_files(self, path: str) -> dict:
        findings = {
            'rsa': [],
            'ecc': [],
            'sha1': [],
            'tls_1.2': [],
            'quantum_vulnerable': []
        }
        
        # Search for weak algorithms
        patterns = {
            'RSA': r'RSA\(|key_size.*2048',
            'ECDSA': r'ECDSA|secp256',
            'SHA1': r'SHA-?1',
            'TLS': r'TLSv1\.2'
        }
        
        # Run grep on codebase
        for algo, pattern in patterns.items():
            result = subprocess.run(
                ['grep', '-r', pattern, path],
                capture_output=True
            )
            if result.returncode == 0:
                findings[f'{algo.lower()}_vulnerable'].extend(
                    result.stdout.decode().splitlines()
                )
        
        return findings

# Migration priorities
priority:
  critical:
    - TLS certificates (most exposed)
    - VPN connections
    - API authentication tokens
  
  high:
    - Database encryption (at rest)
    - File storage encryption
    - Internal communications
  
  medium:
    - Backups
    - Archives
    - Logs
  
  low:
    - Non-sensitive data
    - Public information

# Test PQC implementation
import unittest

class PQCTest(unittest.TestCase):
    def test_ml_kem_roundtrip(self):
        """Test ML-KEM encapsulation/decapsulation"""
        from liboqs import KEM
        
        kem = KEM("Kyber512")
        pk = kem.generate_keypair()
        
        ct, ss1 = kem.encaps(pk)
        ss2 = kem.decaps(kem.export_secret_key(), ct)
        
        self.assertEqual(ss1, ss2)
    
    def test_ml_dsa_signature(self):
        """Test ML-DSA signing/verification"""
        from liboqs import Signature
        
        sig = Signature("Dilithium2")
        pk = sig.generate_keypair()
        
        message = b"Test message"
        signature = sig.sign(message, sig.export_secret_key())
        
        self.assertTrue(sig.verify(message, signature, pk))

# Immediate actions
actions:
  - name: Inventory cryptography
    status: in_progress
    deadline: 2026-Q2
  
  - name: Enable hybrid TLS
    status: pending
    deadline: 2026-Q3
  
  - name: Test PQC in staging
    status: pending
    deadline: 2026-Q4
  
  - name: Deploy PQC to production
    status: pending
    deadline: 2027-Q1

# NIST approved algorithms
algorithms:
  key_encapsulation:
    - ML-KEM-512 (Kyber512)
    - ML-KEM-768 (Kyber768)
    - ML-KEM-1024 (Kyber1024)
  
  digital_signatures:
    - ML-DSA-44 (Dilithium2)
    - ML-DSA-65 (Dilithium3)
    - ML-DSA-87 (Dilithium5)
    - SLH-DSA-SHA2-128s

# Transition checklist
checklist = [
    "Inventory all cryptographic usage",
    "Identify Q-Day impact areas",
    "Enable hybrid encryption in TLS 1.3",
    "Update key management systems",
    "Test PQC in non-production",
    "Plan certificate rotation",
    "Update vendor contracts",
    "Train development teams",
    "Implement monitoring",
    "Plan rollback procedures"
]

# Procrastinating
migration:
  status: not_started
  reason: "quantum computers aren't here yet"

# Start now
migration:
  status: in_progress
  reason: "future-proof our systems"

# Pure PQC (too early)
cipher_suite: "ML-KEM-512-AES256-GCM"

# Hybrid (recommended)
cipher_suite: "ECDHE-ML-KEM-AES256-GCM-SHA384"

# No fallback
algorithm: "only_pqc"

# With fallback
algorithm: 
  primary: "hybrid"
  fallback: "classical_only"