We propose a secure quantum key distribution (QKD) protocol using a single not-so-weak coherent qubit. With two preprocesses for random rotation and compensation, a key bit is encoded to a randomly polarized not-so-weak coherent qubit. We analyze the security of the QKD protocol, which counters the photon number splitting and the impersonation attacks. The estimated mean number of photon, which is less than 6.0, guarantees security. Additionally, we discuss the possibility of quantum secure direct communication.
© 2007 Optical Society of America
Coherence and Statistical Optics
Original Manuscript: September 11, 2006
Revised Manuscript: December 20, 2006
Manuscript Accepted: December 31, 2006
Published: March 19, 2007
Chil-Min Kim, Yong-Wan Kim, and Young-Jai Park, "Secure quantum key distribution with a single not-so-weak coherent pulse," Opt. Lett. 32, 888-890 (2007)