I'm not sure that a Dreambox has SSH. There may be an SSH plugin on IHAD (i-have-a-dreambox.com)
_http://www.i-have-a-dreambox.com/wbb2/thread.php?threadid=35940&hilight=SSH
If you google something like "linux ssh root access" you'll find how to enable it in Linux but I haven't seen an SSH daemon on a Dreambox (sshd)
And if you do feel free to post what you find.
Remember- keep it generic, absolutely no c a b le questions.