Quantum cryptography, animated

This animation by the Centre for Quantum Technologies at the National University of Singapore illustrates the process of quantum key distribution using entangled photons. The goal is for two people in different places to end up with identical keys by measuring these photons. We want these people - usually given the names Alice and Bob - to have a random sequence of 1s and 0s that they can use to scramble (and then unscramble) a message. The presence of entanglement between the photons means that any snooping will be revealed. Note: this animation has no sound.

See also our video series on cryptography:    • Intro to quantum crypto