A Modified Protocol of Quantum Key Distribution Based on Entanglement Swapping

By comparing Cabello's addendum to his quantum key distribution protocol Phys. Rev. A 64(2001)024301, we propose a more convenient modified protocol based on the entanglement swapping which is secure against the eavesdropping strategy addressed by Zhang et al. Phys. Rev. A 63(2001)036301 and other existing types of attack.