2023/07/05 by Ayan Biswas, Biswas, Ayan, Sarika Mishra +9
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Optics (physics.optics) #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2307.02149
openalex publication_date 2023/07/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Satellite-based quantum communication for secure key distribution is becoming a more demanding field of research due to its unbreakable security. Prepare and measure protocols such as BB84 consider the satellite as a trusted device, fraught with danger looking at the current trend for satellite-based optical communication. Therefore, entanglement-based protocols must be preferred since, along with overcoming the distance limitation, one can consider the satellite as an untrusted device too. E91 protocol is a good candidate for satellite-based quantum communication; but the key rate is low as most of the measured qubits are utilized to verify a Bell-CHSH inequality to ensure security against Eve. An entanglement-based protocol requires a maximally entangled state for more secure key distribution. The current work discusses the effect of non-maximality on secure key distribution. It establishes a lower bound on the non-maximality condition below which no secure key can be extracted. BBM92 protocol will be more beneficial for key distribution as we found a linear connection between the extent of violation for Bell-CHSH inequality and the quantum bit error rate for a given setup.