Comparison of error reconciliation protocols in quantum key distribution

• Main Author: Wang, Wenhan.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Computer hardware, software and systems; DRNTU::Engineering::Computer science and engineering::Computer systems organization::Computer-communication networks; DRNTU::Science::Mathematics::Applied mathematics::Simulation and modeling
• Online Access: http://hdl.handle.net/10356/46200
• Institution: Nanyang Technological University

Error reconciliation is an important step in Quantum Key Distribution (QKD) in order to distill a final key free of errors. The efficiency of the reconciliation protocols is important in ensuring the efficiency of a practical QKD system. Simulation has been carried out to compare the various error reconciliation protocols. However, comparison of the protocols through a statistical approach has not been carried out. In this project, three error reconciliation protocols: Cascade, the Cascade-Hash algorithm and Winnow were being compared via the statistical approach with the efficiency based on the error-corrected key rate and the number of bits transmitted across a practical channel using the Transmission Control Protocol/Internet Protocol (TCP/IP), taking into account the additional bits required to perform random shuffling and bit deletion. Furthermore, analysis is being done over two shuffling algorithms of very different properties: Fisher-Yates shuffle and folio interlacement. The protocols, together with the shuffling algorithms, were modeled using various C programs which were then run to obtain the results. Cascade was found to be most efficient in terms of error-corrected key rate, but least efficient in terms of transmission of bits across the channel. The efficiency of the other two protocols depends on the initial mean error rate, the property of the shuffling algorithm and the user’s requirement. It is evident from the results that the efficiency of the three protocols is determined by the trade-off between their strengths and weaknesses, taking into account of practical implementation. Thus, the efficiency of an error reconciliation protocol depends on the situation and the available resources.