Souradyuti Paul Bart Preneel Analysis of Non-fortuitous Predictive States of the RC4 Keystream Generator. 52-67 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2904&spage=52 2003 conf/indocrypt/2003 INDOCRYPT db/conf/indocrypt/indocrypt2003.html#PaulP03