A Combination of BB84 Quantum Key Distribution and An Improved Scheme of NTRU Post-Quantum Cryptosystem

Abstract

The BB84 quantum key distribution (QKD) protocol is based on the no-cloning quantum physic property, so if an attacker measures a photon state, he disturbs that state. This protocol uses two channels: (1) A quantum channel for sending the quantum information (photons polarized). (2) And a classical channel for exchanging the polarization and the measurement information (base sets or filters). The BB84 supposes that the classical channel is secure, but it is not always right, because it depends on the methods used during the communication over this channel. If an eavesdropper gets the sender or the receiver filters or both of them, he can leak some or all bits of the constructed key. In this context, we contribute by creating a protocol that combines the BB84 protocol with an improved scheme of NTRU post-quantum cryptosystem, which will secure the transmitted information over the classical channel. NTRU is a structured lattice scheme, and it is based on the hardness to solve lattice problems in Rn. Actually, it is one of the most important candidates for the NIST post-quantum standardization project.