Multidimensional bell inequalities and quantum cryptography

Abstract

The laws of quantum physics allow the design of cryptographic protocols for which the security is based on physical principles. The main cryptographic quantum protocols are key distribution schemes, in which two parties generate a shared random secret string. The privacy of the key can be checked using Bell inequalities. However, the Bell inequalities initial purpose was a fundamental one, as they showed how quantum rules are incompatible with our intuition of reality. This paper begins with an introduction about quantum information theory, Bell inequalities, quantum cryptography. Then it presents the use of qudits for Bell inequalities and cryptography.