What is the primary motivation for adopting post-quantum cryptography?

• A. To prepare for quantum threats to public-key cryptography
• B. To simplify key management
• C. To replace all encryption with symmetric methods
• D. To increase ciphertext length indefinitely

Answer: (A)

Public-key cryptography is the target here: quantum computers could break the kinds of algorithms that secure key exchange and digital signatures today, such as RSA and elliptic-curve schemes. If those primitives can be cracked, secure channels and authenticating messages become unreliable. Post-quantum cryptography focuses on developing and adopting algorithms that are believed to remain secure in a world with quantum attackers, so we can continue to establish confidential channels and verify identities even when quantum capabilities exist. This is why the primary motivation is to prepare for quantum threats to public-key cryptography. It isn’t about simplifying key management, replacing everything with symmetric methods, or making ciphertexts grow without bound.