Xun Yi Kwok-Yan Lam Yongfei Han Differential Cryptanalysis of a Block Cipher. 58-67 1998 conf/acisp/1998 ACISP http://link.springer.de/link/service/series/0558/bibs/1438/14380058.htm db/conf/acisp/acisp1998.html#YiLH98