Mathematics and Physics Build a New Future for Secure Communication [Guest editors´ introduction]

Cryptography keeps data secret while in transit or at rest, and this property underlies the notions of secure communication, secure identities, and access control on the Internet. These are well-known uses implemented by algorithms and protocols that are the subject of ongoing research and refinement. The field grows with the steady discovery of new forms of and uses for secure communication. These developments make for a vibrant, emerging landscape for privacy and authentication on an ever-shifting physical substrate. In this special magazine issue, four different parts of that landscape are explored.