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Comment by frevd | Hacker News Reader

You can, using some biometric safeties on the controls.

How would biometrics protect from an authorized party controlling the plane he is supposed to control?

Overriding the override ;]. But yeah, it's kind of a race-condition. Not sure, how about some majority vote, enough members on the crew there to vote?

Trying to get a quorum aboard a falling plane. Now that's what I call an extreme democratic procedure ;)

And in a dramatic scenario, rather than "One head, one vote", you'll probably have "One gun, 100 votes" anyway...

That's not foolproof either. There's always a compromise to make: if you have more automation to prevent pilot from being suicidal or making mistakes, you also have more automation that prevents a pilot - or anyone - taking over when the computer control goes wrong.

Let's accept it: we may make things gradually better, but there is no silver bullet that would solve all these problems.

Fine. You authorize the whole crew, not by fingerprint and not by code, but by voice recognition and secret code words per person. Then you allow the override to be overridden by a majority (recursively). Sounds way better than making the door break when a majority of people kicks at them. It is faster than remembering and entering codes, and cannot be overridden by one sick authorized person. An attacker would have to control the whole crew to make them do what he wants, to a level where they actually speak the secret words. In an event where the crew anticipates a crash, giving in on pressure would be the worst option to take.

To prevent attackers from muting all but the required majority of crew members, sensors all over the plane must be able to record any emergency code words spoken in the event of an attack, which will enact certain security measures (depending on the code word could lock or unlock the possibility to enter the cockpit, notify air security etc). This system should of course not be able to be deactivated.

And if you really wanted to make things sure, you could install majority-authorization buttons on every seat setup to be pressed by a percentage of boarded people within a period of mere seconds, which would allow the people on the plane to make a decision. For an attacker it is not possible to make all those people press the button, since he would not know who is not complying.

Of course you can also have some remote mechanism of unlocking, although the security implications of remote authorization and transmission of commands would be complicated to get right and open too many attack vectors.

I guess you are making fun of someone, but that is a good demonstration why too complex procedures are not a good idea.

Any procedure that aircraft crew is supposed to handle also needs to be something that is trained, memorized, and practiced regularly. Certain simplicity is ideal.

No. It is certainly not my intention to make fun of the case that a copilot is able to control a machine and crash it at his will. Lufthansa is saying "there is no system that can prevent this kind of incident". They will have to take the possibility into account that you have to protect the plane against an authorized person as well, and think about possible solutions to this problem. Solving conflicting interests is not an easy task.

In summary, there must be mechanisms to de-authorize personal, by means of majority vote. To prevent an attack vector, biometric systems need to be used to verify other authorized personal safely (it might be far fetched, but measuring certain stress hormons might prevent attackers from controlling authorized personal and using them to override controls as well, and likewise, other authorized people must be able to act, e.g. by having controls that cannot be blocked by any means (re voice recorders all over the plane to enable or disable locks etc, again by majority vote)). Does that sound too futuristic? I wouldn't want to board a plane if I cannot be sure that any and all cases are covered.

Or we can not do all that.

> Then you allow the override to be overridden by a majority (recursively).

Thus rendering the doors essentially useless, as hijackers threaten to kill passengers one-by-one until the crew (who will generally outnumber the 1-2 people in the cockpit) open the door.

Aren't many biometric controls trivial to defeat though?

For instance, to replicate someones fingerprints all you need is a high res photo of their hand from a distance.

Yeah, iris scan isn't safe either if attackers can get the authorized person in their control. Maybe using two random people from the crew would be best, hard to find out for an attacker and still safe against "forgetting" the secret code.

Or, a less high-tech solution: use the knife of your airline meal set to cut away the finger.

Then the airline will move on in the arms race by responding with a fingerprint reader that wants to have a pulse in the finger, and then it doesn't work when the user is in distress and has an extremely high pulse. And then there is an accident and we the armchair security experts come up with more bright ideas.

>Or, a less high-tech solution: use the knife of your airline meal set to cut away the finger.

Last time I had an airline meal, even in first class, the knife "blade" was hard rubber mounted on a blunt metal handle. It could barely cut the food cleanly, never mind someone's finger.

Yes, I was being sarcastic. You do, however, occasionally get real cutlery, even in economy class, with some airlines.

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