bumping proof?

[kennylt]

hey what if you put a third part on the pin set? one that is allways below share line an obsorves all the energy? after all this is what the method is based on

[raimundo]

bumping must cause the plug to move forward a bit, with interlocking gear teeth, on some part, such as the anti shim rim at the front of the lock, any forward movement of the plug could be made to negate turning, these teeth could be so tiny that it would not be a problem for the key but just enough to lock the turning force that accompanies bumpin. the inside of the anti shim rim could be cut with tiny teeth that fit into other tiny teeth in the lip of the cylinder.

[vector40]

It does seem like any mechanism sensitive enough to detect that amount of motion would be awfully easy to false-positive when using a key ordinarily. I mean, I don't push in when I twist a key, but I'm sure there are people who do, and even if they didn't lock it up every time (or often at all), it'd be pretty annoying if it were something you'd have to think about. People don't want to put thought into turning a key.

[kennylt]

cool idea raimundo
this shouldnt be mutch inconveniance if i got the idea correctly it would be something like that protection on the vitamine packeges vich doesnt let you open until there is enough pressure on the lid, in this case the pressure blocks the lock from turning and even turns it backwordsa little bit

[OhMyGodItsFullOfStars]

Funny, i just read a whitepaper and watched a video from toool, and discovered this thread right after.
I didnt see anyone commenting on kennylt's idea of a third pin, to absorb the kinetic energy while the middle pin stays put blocking the shear line. I think that would work, and it could be employed to existing locks.

[samsonai]

The energy, if done correctly, is transfererd to the pins
via the ramps of the depth cuts down the blade during
the forward stroke of the key. The brunt of the force is
sustained by the shoulder of the key. I have yet to see
damage or indication that the tip has hit the back of the
lock and I have never cut off the tip of the key.


So, since the key is cut to the right spacing to allow all pins
to cradle in the depth cuts equally, albeit the deepest cut, what
would allow one pin to absorb the force more than another? I
don't see how any one pin could absorb the force of the blow.
Perhaps I do not understand the components of your proposition.

Can someone clarify this?

[samsonai]

and by the way the plug moves forward this much
0.00001%. If you could make gears detect that why
not just design a pickproof lock. lol

[wtf|pickproof?]

The idea behind the third pin in the stack utilises the phenomenon demonstrated in this java applet:
http://www.walter-fendt.de/ph11d/nwiege.htm
The third part of the pinstack absorbs all the kinetic energy which was introduced by the bumping key. This way the middle part is still blocking at the shearline.

I have no idea if this would work. I think it's mostly dependent on the mass of the parts of the pinstack. But I've never heared a word about masterkeyed locks beeing imune to bumping.

As bumping depends on elastic collisions, maybe pins with differing elasticity, or even springs with different elasticity may make bumping harder.

Another way to protect against bumping is having pins like those utilized in this EVVA locks:

which basically a combination of wafer and and pin-tumbler.(please correct me if I'm wrong about this)

Disctumbler and warded locks aren't subject to bumping attacs either. Basically bumping will "only" work on pin tumbler locks. So any combination of the pintumbler and any other type of locks will secure it against _plain_ bumping attacs.

wtf|pickproof?




There are other known types of locks where bumping won't help

[wtf|pickproof?]

There are days were I whish I had an edit button.

wtf|pickproof?

[samsonai]

I understand now I will have to try that and see if it works.
Until then thanks for the info.

David Storm

[MrB]

I understand that the "third pin" idea is in fact used in some high quality locks as a protection against pick guns and bumping. A bearing ball can be placed between the driver pin and the spring, so that when the lock is bumped the ball absorbs some of the kinetic energy and prevents the driver pin from lifting so much.