Kvantumkulcselállítás

Kvantumkulcselállítás refers to the process of securely establishing a shared secret key between two parties using principles of quantum mechanics. This is primarily achieved through quantum key distribution (QKD) protocols. Unlike classical cryptography which relies on mathematical complexity, QKD leverages the laws of physics to ensure the security of the key exchange.

The most well-known QKD protocol is BB84, developed by Charles Bennett and Gilles Brassard in 1984. In BB84, the sender (Alice) encodes key bits onto quantum states of photons, such as their polarization. The receiver (Bob) then measures these photons. The fundamental principle of quantum mechanics, the uncertainty principle, dictates that any attempt by an eavesdropper (Eve) to measure the photons will inevitably disturb their quantum state. This disturbance can be detected by Alice and Bob, alerting them to the presence of an eavesdropper and allowing them to discard the compromised key.

If no eavesdropping is detected, Alice and Bob can then publicly compare a subset of their transmitted bits to confirm the accuracy of their key. This process ensures that the shared secret key is known only to them and that its integrity has been maintained. Kvantumkulcselállítás, through QKD, offers a theoretically unbreakable method for key exchange, providing a significant advantage over classical methods which are vulnerable to future advancements in computing power, particularly quantum computers.