La crittografia quantistica come occasione per introdurre alcune proprietà fondamentali dei sistemi quantistici

The article describes a teaching proposal in which some fundamental properties of quantum systems are presented through the development of quantum cryptography protocols. The idea is the use of these properties as operational tools in a context that can stimulate students’ curiosity and interest. After a brief introduction on the methods cryptography, we present some general features of the quantum theory with a special reference to the two-level systems (quantum bit, qubit) and to the behaviour of polarised pho-tons. Subsequently, the BB84 protocol is described and a simulation play of quantum key transmission – to be played by groups of students – is proposed.