Quantum Key Distribution: a gentle introduction

The potential arrival of quantum computers poses a threat to the most common public key encryption system in use today. However, quantum principles can be employed to create systems that allow theoretically secure key exchange schemes. In this talk we give a gentle introduction to how and why quantum key distribution works, plus we explore some of the implementation difficulties and how they affect the security of the schemes. Practical schemes are described and some of the exciting, near developments in the field are described. The talk hopes to equip the audience to consider the question of whether quantum based encryption schemes are the answer to the threat posed by quantum computers.