Quantum Computing and Cryptography
Dr. Nico Döttling (Helmholzt Center for Information Security (CISPA) in Saarbrücken)

In the early 1990s cryptography went into a foundational crisis when efficient quantum algorithms were discovered which could break almost all public key encryption schemes known at the time. Since then, an enormous research effort has been invested into basing public key cryptography, and secure computation in general, on problems which are conjectured to be hard even for quantum computers. This research program has been resoundingly successful, leading to unexpected developments, such as the discovery of fully homomorphic encryption schemes. Furthermore, cryptography research has now moved beyond just "post-quantum security”, i.e. security against quantum adversaries, and investigates cryptographic protocols for a (still hypothetical) quantum world, where not just adversaries, but also honest users have access to scalable quantum computers and quantum communication channels. This enables applications such as quantum money, which are impossible using purely classical information. In this talk I will give an overview of the field and some of the (in my opinion) most challenging open problems.