Affordable quantum cryptography system for mobile devices

The today’s technology allows us to design simple quantum cryptography circuits embeddable in mobile devices to ensure the maximum security in money transfer and controlled access. It is known that the quantum cryptography protocols allow a virtually perfectly secure key generation and exchange process. This technology uses the quantum property which states that orthogonally polarized states can be completely discriminated, thus can be used to codify information. The system presented in this paper adopts a properly costumized BB84 protocol. The hardware instrumentation includes two fast PCs with acquisition card, a 4-channels transmitter, 4 high-efficiency LED diodes, a receiver with 4 highsensitivity photodiodes, and suitable optic devices. Transmitter and receiver consist of two custom electronic cards with suitable software for random bit generation and decoding procedures The software also allows to reconstruct the shared secure key. The system has been realized with the purpose to be included in mobile devices and to allow each one to afford the quantum cryptography security level, both for ATM operations and e-commerce transactions.