الفهرس 
Cryptography in Literature
Proposed QSDC system – Modelling and SimulationOnly 14 pages are availabe for public view
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Abstract
Quantum Cryptography has been playing an important role in communications after the reveal of vulnerabilities of classical channels. The main aim of encryption is to guarantee the security of the messages among communicators, without reducing the efficiency of communication channel. The most popular idea was quantum key distribution which unfortunately leads to the loss of lots of qubits since many of them have to be discarded. In 2002, Quantum secure direct communication QSDC was launched based on transmitting directly the secret messages without first establishing a key to encrypt them. It does not require any additional classical information in communications.
While most of the researches on channel security have focused on point to point communication, little attention was given to multi nodes networks. In this study, the possibilities of loopholes in multi-sites networks using quantum secure direct communication encryption protocols are analyzed. Several solutions are proposed. Depending on the installed topology (linear, ring, star and partially meshed) and on the distance between the nodes, a different solution is proposed.
In this study as well, a complete modeling and simulation has been done for a QSDC communication system using quantum photonic simulator and compared to experimental results. Security enhancements has been done by introducing decoy state function to the system and dispersive compensation techniques to drive the system to match practical fiber lengths which are required in commercial systems.