Browsing Theses by Supervisor "Lütkenhaus, Norbert"
Now showing items 1-10 of 10
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Application of the Flag-State Squashing Model to Numerical Quantum Key Distribution Security Analysis
(University of Waterloo, 2020-09-18)The squashing model proof technique is a powerful tool in proving security of quantum key distribution (QKD) protocols since it reduces the dimension of the associated computational problem from infinite to finite. In the ... -
Assessing the Practicality of a Simple Multi-node Quantum Repeater
(University of Waterloo, 2017-10-25)This thesis assesses the theoretical performance of a realistic multi-node quantum repeater that is implementable with current technology. A quantum repeater, by definition, allows for communication rates in a channel to ... -
Decoy-State Quantum Key Distribution with Arbitrary Phase Mixtures and Phase Correlations
(University of Waterloo, 2022-01-26)We formulate a general method to find bounds on the statistics of states passing through an unknown channel from the statistics of another set of states. We pay special attention to the application of this method to ... -
Optical Quantum Communication & Cryptography with Temporarily Trusted Parties
(University of Waterloo, 2019-09-19)The work in this thesis can be divided into three parts. The first two parts deal with optical quantum communication protocols and the third part deals with quantum cryptography. The first part of the thesis is a step ... -
Practical Quantum Fingerprinting and Appointment Scheduling
(University of Waterloo, 2017-10-24)Quantum protocols for many communication tasks have been found which significantly improve on their classical counterparts. However, many of these protocols are beyond the reach of current technology. In this work, we find ... -
Security Analysis of Quantum Key Distribution: Methods and Applications
(University of Waterloo, 2021-09-27)Quantum key distribution (QKD) can be proved to be secure by laws of quantum mechanics. In this thesis, we review security proof methods in Renner's framework and discuss numerical methods to calculate asymptotic and finite ... -
Security Proofs for Quantum Key Distribution Protocols by Numerical Approaches
(University of Waterloo, 2017-10-25)This thesis applies numerical methods to analyze the security of quantum key distribution (QKD) protocols. The main theoretical problem in QKD security proofs is to calculate the secret key generation rate. Under certain ... -
Symmetric Extendability of Quantum States and the Extreme Limits of Quantum Key Distribution
(University of Waterloo, 2016-10-13)We investigate QKD protocols with two-way classical post-processing that are based on the well-known six-state and BB84 signal states. In these QKD protocols, the source (Alice) sends quantum signals to the receiver (Bob), ... -
Tools for the Security Analysis of Quantum Key Distribution in Infinite Dimensions
(University of Waterloo, 2021-08-12)We develop a method to connect the infinite-dimensional description of optical continuous-variable quantum key distribution (QKD) protocols to a finite-dimensional formulation. The secure key rates of the optical QKD ... -
Toward standardization of Quantum Key Distribution
(University of Waterloo, 2020-09-03)Information security becomes an inseparable part of our everyday life. An encryption method widely used today is public-key encryption. The security of this method is based on a hard to solve mathematical problems against ...