diff --git a/xCAT-server-2.0/lib/xcat/plugins/mknb.pm b/xCAT-server-2.0/lib/xcat/plugins/mknb.pm
index b5628b311..c38df2b56 100644
--- a/xCAT-server-2.0/lib/xcat/plugins/mknb.pm
+++ b/xCAT-server-2.0/lib/xcat/plugins/mknb.pm
@@ -68,7 +68,9 @@ sub process_request {
       return;
    }
    mkpath($tempdir."/root/.ssh");
+   chmod(0700,$tempdir."/root/.ssh");
    copy("/root/.ssh/id_rsa.pub","$tempdir/root/.ssh/authorized_keys");
+   chmod(0600,"$tempdir/root/.ssh/authorized_keys");
    if (-r "$installdir/postscripts/hostkeys/ssh_host_key") {
       copy("$installdir/postscripts/hostkeys/ssh_host_key","$tempdir/etc/ssh_host_key");
       copy("$installdir/postscripts/hostkeys/ssh_host_rsa_key","$tempdir/etc/ssh_host_rsa_key");