Youngdai Ko Deukjo Hong Seokhie Hong Sangjin Lee Jongin Lim Linear Cryptanalysis of SPECTR-H64 with Higher Order Differential Property. 298-307 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2776&spage=298 2003 conf/mmmacns/2003 MMM-ACNS db/conf/mmmacns/mmmacns2003.html#KoHHLL03