Rigorous Security Proofs for Practical Quantum Key Distribution

This thesis is concerned with rigorous security analyses of practical Quantum Key Distribution QKD protocols, using a variety of modern proof techniques. The main results are as follows. First, we establish a security proof for variable-length QKD protocols against IID collective attacks, and...

Quantum CDMA-Based Continuous Variable Quantum Key Distribution Using Chaotic Phase Shifters

We present a quantum code-division multiple-access q-CDMA framework for multiuser continuous-variable quantum key distribution CV-QKD over a shared quantum channel. The proposed architecture employs chaotic phase shifters to encode and decode quantum states, enabling efficient multiplexing and...

Finite-Size Security of QKD: Comparison of Three Proof Techniques

We compare three proof techniques for composable finite-size security of quantum key distribution under collective attacks, with emphasis on how the resulting secret-key rates behave at practically relevant block lengths. As a benchmark, we consider the BB84 protocol and evaluate finite-size...

An Introductory Review of the Theory of Continuous-Variable Quantum Key Distribution: Fundamentals, Protocols, and Security

Continuous-variable quantum key distribution CV-QKD has emerged as a promising approach for secure quantum communication, offering advantages such as high key generation rates, compatibility with standard telecommunication infrastructure, and potential for integration on photonic chips. This revi...

Secure One-Sided Device-Independent Quantum Key Distribution under Collective Attacks with Enhanced Robustness

We study the security of a quantum key distribution QKD protocol under the one-sided device-independent 1sDI setting, which assumes trust in only one party's measurement device. This approach effectively provides a balance between the experimental viability of device-dependent DD-QKD and the...