Yipee ! At last a breakthrough - using the encrypted string (S-1-...) as <a href="http://user.name">user.name</a> java property work ! You should update the doc. Thanks everybody for the help.           /jog <div class="gmail_quote">On Tue, Jun 10, 2008 at 3:38 PM, Jacques-Olivier Goussard <<a href="mailto:jogoussard@gmail.com">jogoussard@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Guys, I believe I made some progress here. Looking at the logs whem murmur connects, I can see that it is using the EXTERNAL protocol and: 13736: server: got command "AUTH EXTERNAL 532d312d352d32312d35323730323739332d31 3939363639313833372d3331353537363833322d32383035" 13736: server: Trying mechanism EXTERNAL 13736: server: data: 'S-1-5-21-52702793-1996691837-315576832-2805' This SID is the same authentication string used in cygwin for ex to encrypt the password. If I compare to the case of the java client, I get: 13932: server: got command "AUTH EXTERNAL 6a6f67" 13932: server: Trying mechanism EXTERNAL 13932: server: data: 'jog' which comes from the fact that the java client blindly uses the <a href="http://user.name" target="_blank">user.name</a> property as credential. Now, I still your help there: anyone knows how and where I can get this authorization string (the S-1-.. etc one) from java or win32 api ? I know that asking this to a linux bunch is almost hopeless, but who knows... Cheers                /jog </blockquote></div>