This is a translation of an anonymous report published about Einstein’s seminar in Berlin in November of 1931 dicussed in detail in Chapter 1. The report describes Einstein discussing the meaning of Heisenberg’s uncertainty relations and describing his famous photon-box thought experiment.

This is a translation of notes by Schrödinger wherein he draws the implications of Einstein’s photon-box thought experiment.

In this chapter we present an alternative path to base security in challenging settings. We will discover that physical assumptions on the adversary, such that they have a bounded or a noisy quantum memory, can be leveraged to design secure protocols for tasks, such as 1-2 oblivious transfer, for which there cannot exist an unconditionally secure protocol. To prove security we make a fresh use of uncertainty relations introduced earlier in the context of quantum key distribution.

A quantum key distribution (QKD) protocol allows two honest users Alice and Bob to harness the advantages of quantum information processing to generate a shared secret key. The most well-known, and indeed the first QKD protocol that was discovered, is called BB’84, after its inventors Bennett and Brassard and the year in which their paper describing the protocol was published. In this chapter we describe the BB’84 protocol and we introduce the main ideas for showing that the protocol is secure.