  We show the enhancement of distillable key rate for quantum key
distribution(QKD), by local filtering, for several bound entangled states.
Through our work it becomes evident that the local filtration operations, while
transforming one bound entangled state to another, have the potential to
increase the utility of the new state for QKD. We demonstrate three examples of
`one way distillable key rate' enhancement by local filtering and in this
process, discover new bound entangled states which are key distillable.
