E91 Protocol

The E91 protocol is a quantum key distribution method that uses entangled particles—pairs of linked quantum states—to securely generate a shared encryption key between two parties. When one party measures their particle, the result instantly determines the other’s measurement, no matter the distance. This interconnectedness ensures that any eavesdropper attempting to intercept the communication disturbs the system and can be detected. The protocol leverages the principles of quantum mechanics to create an inherently secure way of sharing secret keys, making it practically impossible for anyone outside the trusted parties to access the information without detection.