UW Computer Security Research and Course Blog

As i’m sure everyone already aware of, one way our country (and many others) directs traffic is with these things call traffic lights. We place them at intersections, at about a one to one ratio of oncoming lanes to traffic light boxes. A box has three states, green, yellow, red. Green means you can go, yellow means red is imminent, and red means don’t go. Of course.

Now, how are these lights choosing which state do display? A set of lights at an intersection should display a setting that does not give multiple lanes the right of way to crossing paths. But when do we change states? In the beginning, it was all done off timers. At set intervals the right of way was changed from one lane to another, ect. However, then people realized that depending on the time of day, we might want different settings. And then people were like, hey lets put in sensor’s to figure out if there is car waiting! These things are usually are metal detects, but weight detectors exist also. All these strategies used the idea that each intersections should be independent of all the others. But then humans got the idea that if we could get ‘waves’ of green lights to happen, we could get even more efficiency. This requires intersections to talk to other intersections, as well as the ability to program in this information, and maintain/reset it as needed.

Many intersections also have buttons for pedestrian’s to push if they wish to walk across. This would give another signal to the lights, and the lights would queue up this request, and execute it eventually. Emergency vehicles also have a similar ability (and in some cases public transportation such as buses and light rail), which is called traffic signal preemption. Depending on the implementation, it can use radio waves, infrared, strobe lights, and audio signals from a siren to trigger. This will switch only the emergency vehicle’s path to green, and everyone else to red.
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Security Review: Bodyguard
Overview:
Bodyguards are people who protect their clients from various treats such as assaults, assassination, and kidnapping. Depending on the importance of the client who is being protected, some clients might have a team of bodyguards while another might just need only one. The general minimum requirements for bodyguards are trained to use firearms, unarmed combats, tactical driving, and first aid to ensure the safety of the client. In addition, for bodyguards who need to protect more important person or who are working in teams, they tend to have specializations for various skills like crowd control, protective escort, and finding electronic threats.

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