Comment on "A Random Quantum Key Distribution Achieved by Using Bell   States"
  In a recent paper [J. Opt. B: Quantum Semiclass. Opt. 5 (2003) 155-157], a quantum key distribution scheme based on entanglement swapping was proposed, which exhibited two improvements over the previous protocols. In this Comment, it is shown that the scheme has no properties as been discussed. 
Sujuan Qin, Qiaoyan Wen, Fuchen Zhu