Finite key size analysis of two-way quantum cryptography

• Main Authors: Shamsul Shaari, Jesni, Mancini, Stefano
• Format: Article
• Language: English
• Published: MDPI 2015
• Subjects: QC Physics
• Online Access: http://irep.iium.edu.my/47019/1/entropy-17-02723.pdf; http://irep.iium.edu.my/47019/; http://www.mdpi.com/1099-4300/17/5/2723

Quantum cryptographic protocols solve the longstanding problem of distributing a shared secret string to two distant users by typically making use of one-way quantum channel. However, alternative protocols exploiting two-way quantum channel have been proposed for the same goal and with potential advantages. Here, we overview a security proof for two-way quantum key distribution protocols, against the most general eavesdropping attack, that utilize an entropic uncertainty relation. Then, by resorting to the “smooth” version of involved entropies, we extend such a proof to the case of finite key size. The results will be compared to those available for one-way protocols showing some advantages.