Dukjae Moon Kyungdeok Hwang Wonil Lee Sangjin Lee Jongin Lim Impossible Differential Cryptanalysis of Reduced Round XTEA and TEA. 49-60 2002 conf/fse/2002 FSE http://link.springer.de/link/service/series/0558/bibs/2365/23650049.htm db/conf/fse/fse2002.html#MoonHLLL02