I can't tell what's causing the ClassCastException from that stack trace, however the DatabaseServerLoginModule login module that you're using is a JBoss AS-specific login module, and won't work as is with Seam security. The unfortunate truth is that each app server implements security differently, and even though they might all use JAAS, the specification isn't specific enough to ensure compatibility. I agree it would be nice to have some kind of layer/adapter that allowed at least the JBoss login modules to be used, however this won't be available in the initial security release. For the time being if you are authenticating against a database I recommend using SeamLoginModule, following the Seamspace example. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4003272#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...