Over the last decades, cryptography and computer security have gained central importance for the safety and prosperity of our open digital societies. Among others, they are essential for protecting critical public infrastructures; the privacy of citizens; our political institutions and their elected representatives; corporate and private intellectual property; the existing internet and the imminent internet of things; the worldwide financial system; international borders and travels; safety-critical commercial products, including pharmaceuticals; and the global supply chain.The CAS Research Focus “Physics and Security” carefully investigates how physical methods can complement the currently prevailing, but often vulnerable digital security solutions in the above sectors. Its aim is to enable strongly improved or even completely new security features via the explicit involvement of physics. To name three illustrating examples, the Research Focus exploits quantum phenomena to realize cr
