Seokhie Hong Deukjo Hong Youngdai Ko Donghoon Chang Wonil Lee Sangjin Lee Differential Cryptanalysis of TEA and XTEA. 402-417 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2971&spage=402 2003 conf/icisc/2003 ICISC db/conf/icisc/icisc2003.html#HongHKCLL03