Carlos Javier Hernández Castro L. Javier García-Villalba Julio César Hernández Castro José María Sierra On MARS's s-boxes Strength against Linear Cryptanalysis. 79-83 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2669&spage=79 2003 conf/iccsa/2003-3 ICCSA (3) db/conf/iccsa/iccsa2003-3.html#CastroVCC03