Matt Weir Sudhir Aggarwal Breno de Medeiros Bill Glodek Password Cracking Using Probabilistic Context-Free Grammars. 391-405 2009 IEEE Symposium on Security and Privacy http://dx.doi.org/10.1109/SP.2009.8 conf/sp/2009 db/conf/sp/sp2009.html#WeirAMG09