چکیده (انگلیسی):

This study provides a simple variation of the protocol of
quantum key expansion proposed by Hwang. Some weaknesses
relating to the step of public discussions for error detection are
analyzed and an attack strategy, allowing the eavesdropper to get
partial information about the used bases, is put forward. Using the
One-Time Pad cipher, we propose a possible scheme which is secure
against the presented attack.