@ARTICLE{Li:CSF2008, author = {Chengqing Li and Shujun Li and G. \'{A}lvarez and Guanrong Chen and Kwok-Tung Lo}, title = {Cryptanalysis of a chaotic block cipher with external key and its improved version}, journal = {Chaos, Solitons \& Fractals}, year = {2008}, volume = {37}, number = {1}, pages = {299-307}, doi = {10.1016/j.chaos.2006.08.025}, note = {preprint available online at \url{http://www.hooklee.com/pub.html}}, }