My father would say: "locks are made for honest people"

"Quantum cryptography isn't as invincible as many researchers thought: a commercial quantum key has been fully hacked for the first time.

"In theory, quantum cryptography — the use of quantum systems to encrypt information securely — is perfectly secure.

"In practice, however, no quantum cryptographic system is perfect and errors will creep in owing to mundane environmental noise."

Author: Zeeya Merali at "Quantum crack in cryptographic armour (Nature)"