Quantum Key Distribution Using Entangled Photons

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. 

Quantum Cryptography Explained

With recent high-profile security decryption cases, encryption is more important than ever. Much of your browser usage and your smartphone data is encrypted. But what does that process actually entail? And when computers get smarter and faster due to advances in quantum physics, how will encryption keep up?

How Quantum Key Distribution Works (BB84 & E91)

Discussion about how quantum key distribution methods based on measuring the polarization of photons can be used to keep communications secure. In particular, the methods of  Bennett and Brassard (BB84) and Ekert (E91) are explained.

Contents

00:00 - Introduction

00:25 - One-time pad

02:17 - Public key cryptography

03:22 - Photon polarization

04:46 - BB84

08:31 - No-cloning theorem

09:06 - Quantum networks

09:55 - E91

Why Quantum Computing Requires Quantum Cryptography

Quantum computing is cool, but you know what would be extra awesome - a quantum internet. In fact if we want the first we’ll need the latter. And the first step to the quantum internet is quantum cryptography.