Jyh-haw Yeh Marion Scheepers Wen-Chen Hu Modifying YCN key assignment scheme to resist the attack from Hwang. 435-440 2005 95 Inf. Process. Lett. 4 http://dx.doi.org/10.1016/j.ipl.2005.05.008 db/journals/ipl/ipl95.html#YehSH05