That accident was definitely not in connection with an unauthorized access to the cockpit. The issue was cockpit blocking.

BTW fingerprinting is not only humiliating as it was reserved for criminals for a long time. It also can be forged as the pictures of the fingerprint of German secretary of defence as can be found in many media releases in Germany:

http://www.hardwareluxx.de/index.php...bdruckes.html#

The best way would be that the two pilots have to be within the secure cockpit area during the flight. Some changes to the floor plan with a cockpit crew lavatory would do it.

Additionally the purser should have some kind of emergency door opening code or device.