Why is post-quantum cryptography treated as a migration priority?

• A. Because quantum computers threaten current public-key schemes
• B. Because it is a regulatory requirement
• C. Because it reduces energy usage
• D. Because it increases key length automatically

Answer: (A)

Public-key cryptography is vulnerable to quantum attacks, which is why post-quantum cryptography is treated as a migration priority. Quantum computers running algorithms like Shor’s can factor large numbers and compute discrete logarithms efficiently, breaking RSA, DSA, ECDSA, and Diffie-Hellman—the backbone of many secure key exchange and digital-signature schemes used today. If a powerful quantum computer exists, encrypted communications could be decrypted and forged signatures could undermine authenticity, compromising confidentiality and integrity. Because attackers could harvest encrypted data now and decrypt it later, organizations push to adopt quantum-resistant algorithms before widespread quantum capability arrives. Migrating takes time due to standardization, interoperability, and deployment considerations, so starting the transition early helps maintain security over the long term. This is not primarily about regulatory requirements, energy use, or automatic key-length changes.