activity
20242026
collaborators

5 papers

quant-ph2026

A rigorous and complete security proof of decoy-state BB84 quantum key distribution

Devashish Tupkary, Shlok Nahar, Amir Arqand +2

We present a rigorous and complete security proof of the decoy-state BB84 quantum key distribution (QKD) protocol. Our analysis aims to achieve a high standard of mathematical rigo…

quant-ph2025

Generalized Rényi entropy accumulation theorem and generalized quantum probability estimation

Amir Arqand, Thomas A. Hahn, Ernest Y. -Z. Tan

The entropy accumulation theorem, and its subsequent generalized version, is a powerful tool in the security analysis of many device-dependent and device-independent cryptography p…

quant-ph2025

Finite-size analysis of prepare-and-measure and decoy-state QKD via entropy accumulation

Lars Kamin, Amir Arqand, Ian George +2

An important goal in quantum key distribution (QKD) is the task of providing a finite-size security proof without the assumption of collective attacks. For prepare-and-measure QKD,…

quant-ph2025

Marginal-constrained entropy accumulation theorem

Amir Arqand, Ernest Y. -Z. Tan

We derive a novel chain rule for a family of channel conditional entropies, covering von Neumann and sandwiched Rényi entropies. In the process, we show that these channel conditi…

quant-ph2024

Mutual information chain rules for security proofs robust against device imperfections

Amir Arqand, Tony Metger, Ernest Y. -Z. Tan

In this work we derive a number of chain rules for mutual information quantities, suitable for analyzing quantum cryptography with imperfect devices that leak additional informatio…