Qutrit based quantum key generation protocol with self checking mechanism

A protocol using qutrit has been conceived of for quantum key generation. Here, key is embedded in the data string as impurity and one of the qutrit states, named as fencing state is used to discriminate the location of key in the main data string. A one way function known to the legitimate users is used to determine the subsequent basis once the fencing state is settled. Since impurity count is same before and after the fencing state, it provides self checking mechanism for detection of error in the quantum channel, if present, thereby providing better security for key extraction. As it needs no privacy amplification, key generation rate is improved to an appreciable extent.