Simulation of Quantum Cryptography Based on Ekert Protocol

Abstract

Quantum cryptography is new science that relies on the use of protocol designed to exploit quantum mechanical phenomena to achieve the secrecy of cryptographic keys. The purpose of quantum key distribution is for two correspondents, who share no secret information initially, to agree on random keys, which remain secret against attacks from more powerful analytic or computational tools. In this thesis: simulation software for a quantum cryptography based on Ekert – protocol was built. Ekert protocol based on Bell's theorem that can expose eavesdroppers by violated Bell's inequality. Error can occur in quantum transmission due eavesdropping and system inefficiencies. Thus, error elimination technique was implemented. After Error elimination an important mathematical technique called privacy amplification was implemented. The simulation software was built in Borland Delphi language version 7. The simulation result was displayed in an interactive manner with respect to the software user, which explains the effect of number of EPR photons pair on number of coincidences, expected error and Bell's parameter, in case of no-eavesdropping. Also effect of point wise privacy amplification parameters on Eve's information was discussed. In Addition, some examples of encryption and decryption of message was presented to explain the successful of software.