The security at airports, and 3D body scanners in particular, have been in the news a lot recently. The reason I wanted to write about this is that it demonstrates the reactionary way some security is implemented, while actually making things worse for everyone.

It seems that there are two types of security measure: those that reassure the public that something is being done to protect them, and those that actually help. The former is usually a lot less effective than the latter.

Consider traditional airport security. The departure lounge of an airport is considered a “sterile” environment; all of those in it have been screened. For many years, the visible side of this primarily consisted of an x-ray of carry-on luggage and a metal detector for people to walk through. These devices were designed to prevent people bringing knives and guns on board. In addition, hold-baggage cannot travel in an aircraft without an associated passenger as, in general, people don’t want to blow themselves up.

After entering the departure lounge, a passenger has entered into the “sterile” airline system: people transit through different airports and arrive at totally different destinations via different airlines, often without re-screening in transit.

The question is: what type of attack will this actually prevent? Consider the holes in the sterile environment: the baggage handlers, terminal shop staff, flight crews, maintenance workers and the physical security of the airport perimeter.

The additional security measures brought in over the last few years haven’t really addressed the holes, they simply reinforce the idea that something is being done to protect the travelling public. First it was the shoe scanner. Then belts had to come off, liquids were banned and now we have full body scanners. All of these can be circumvented. All of this inconveniences the travelling public, which I wouldn’t mind so much if someone could convince me that there is a point to it.

I will, like most people, grudgingly comply, but I wonder what measures are put in place to determine whether the benefits justify the cost and who actually makes that call. It is possible to opt-out of the enhanced screening (at least in the US), but this means you will be patted down physically, which can be traumatic for some people, especially kids.

These new controls are also inconsistently applied across the network of airports and some airports can opt-out of the TSA programme. I have, inadvertently, walked through a metal-detector at Heathrow with a solid, stainless-steel watch and been through multiple airports with bottles of water. For any control to work, it has to be applied consistently.

This post may come as a surprise as security people are often portrayed as wanting to lock down the world but I am of the belief it is both impossible and undesirable to live in a 100% risk-free environment and a balance has to be struck between security and preventing people getting on with their lives. What I don’t like are controls that are inconsistent and not comprehensive.

Bruce Schneier has much to say on this topic here.

Here’s a video from the TSA on airport security:

The BBC have an article on the balance between civil liberties and security.