Quantum computers: the ultimate hacking machines (WHY2025)

This is a first introduction to quantum computers. This is a first introduction to quantum computers: no prior background needed. We will discuss how quantum mechanics, a theory of microscopic particles, contains counter-intuitive effects like superposition and entanglement. Schrödinger’s cat is an iconic example, where the poor animal is both dead and alive at the same. Interestingly, the same laws of nature make it possible to build an extended set of algorithms, with speedups beyond what we can achieve ‘classically’. I’ll show how we can program today’s quantum computers and show a short live demonstration of the Python package Qiskit. We will learn how to write code that creates something equivalent to Schrödinger’s cat. Then, we will look at one of the most impactful applications. Quantum computers turn out to be incredible hacking machines, making it straightforward to crack widely-used encryption schemes such as RSA and Elliptic Curve Cryptography. We will discuss how long it will take until we have sufficiently large devices, and what alternative cryptography we can fall back to. Licensed to the public under https://creativecommons.org/licenses/by/4.0/ about this event: https://program.why2025.org/why2025/talk/CDGWTU/