Above is how easy it is to attack master key systems. Both my roommate and I had separate rooms with individual locks. We also both had keys for our doors but none of the other rooms in the building. I dissembled the first lock and measured all of the pins in the 5 cylinders, the first row in the graphic above depicts this. If I only had one lock then I would have a lot of possible master keys to cut since each cylinder can shear at 2 locations that is 2*2*2*2*2 possible shear lines or 32 keys to cut. But since I had access to two locks,with it’s measurements in the second row, I narrowed it down to 1 possibility. I should mention that having a second lock will not guarantee you to one master key combination. Depending on how the system is cross keyed you might have to use trial and error to find the grand master key and not just a sub master key.

Above is the key that I hand filed to the master key dimensions, and it worked on all of the doors.

If the key system used patent controlled keys this attack would have been a little bit more of a hassle since I would have to destroy my key to make the master. Ways to protect against this would be to use a patent controlled key and a 1 cut for the master shear line, since its easier to remove material then add it to an existing key. Also a determined person will always be able to exploit a master keyed system so it’s important to take any rooms that need to be secure off the master key system. Room examples would be server rooms, records rooms, main office etc.

My only motivation in all of this was curiosity, no ill intent.Please do not use any of this material for illicit activities. You should only pick locks that belong to you, or where you have explicit permission from the owner.

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A computer can only work with discrete values, not continuous ranges. A curve is a mathematical model for an infinite number of points but a computer simply can not handle an infinite number of points so it slices the curve and models it as a series of points connected with straight lines. This reduces the continuous range of the curve down to a finite number of points. You may be asking yourself how many points is good enough. Well in simply depends on how good of an approximation you want, notice that 10 segments is already very close to approximating the curve below.

Going back to how this applies to slicing the model. The only difference between what I described above and how it applies to the model is that the above case shows a 2-D shape being approximated with lines. In the model we have a 3-D shape that is approximated with triangles. Triangles because they represent a surface with the least amount of points, just like how a line represents a 2-D curve with the least amount of points.

Shown above is the model after it has been sliced up into a finite number of triangles. The printer I used to create this object creates layer that around .001 inches thick and uses wax to fill in voids so it always is printing on a solid surface. The wax can be seen in the picture below.

After the print is complete it is put into an oven that melts the wax off of the part.

Finally I painted the Die, by using some acrylic paint and a calligraphy pen tip.

]]>Upon first glance the object above may seem like an artifact they pulled out of the Roswell crash but it is actually an exuberantly complex die.The model above represents a 20-sided die that is numbered in base 3 math, oppose to our more familiar base 10 system.

So how do I read this Damn thing?

The numbering system on the die is understandably unfamiliar but after you are exposed to how this die works you might have more of an appreciation for numbers in general!

Today we use base 10 math, meaning that we require 10 symbols to fully develop all of the quantities we can conceive. Starting at 0 then go to 9, when we get to 10 we have to start over counting with the addition of another digit. Base 3 math means we can represent all the quantities out there but only use 3 symbols. In the case of this die there can be 0,1,or 2 grooves on the three sides. Each side represents a digit just like in our base 10 system. We are familiar with the 1’s,10’s and 100’s place, in this system there is a 1’s, 3’s, and 9’s place.The indexing circle gives you a point of reference on each triangle that lets determine which numeral place each side represents. Starting at the dot and going clockwise there is the 1’s side then the 3’s side and finally the 9’s side.

The following side can be read in the following manner. Starting at the dot we have 1 notch on the 1’s side, 2 notches on the 3’s side, and 1 notch on the 9’s side.

1*(notches on side 1 side)+3*(notches on 3 side)+9*(notches on 9 side)

1*(1)+3*(2)+9*(1)=16

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