Defeating Bumping

[cracksman]

First off, very nice illustration

If you used small cylinders of that "space aged NASA" stuff they use in beds (don't know if you have seen the commercials with the glass of wine with the girl jumping on the bed) you could probably replace the springs with it and effectively prevent bumping. I don't think it would hold up to weathering, lubricants or anything like that though. What you propose is basically a master keyed system, which I believe is relatively easy to bump, easier to pick anyways. I'm not sure a heavier metal would work, it would make it more difficult, but not impossible.

If you used a metal that could be magnetized for both top and bottom pins you might be able to prevent it. Thats the only thing I can think of that you could just "drop in" without modification. Of course you have to mill the new pins.

P.S. since we usually use some kind of steel for our picks it could also make it a real pain to try to pick magnetized pins. As far as the physics or magnetics I'm talking out my arse, but I can't really see why that might not be a solution. Add a oppositely charged "top pin cover thingy" that repels your top pin and it might work better.

Good Luck, it probably won't work and economically might not be viable either

[ccbiker]

Well the key it to make the weight of the top pin to equal or exceed the wieght the the middle pin. Spring pressure is not a factor really. See the animation below to get what I want the top pin to do as opposed to the other 2 pins.



Assume that one of the balls on the end is the key, the 2 in the middle are the normal pins, the last ball on the end is the "new" pin on top.

Yeah, a greater mass on the top pin would yield a lower initial velocity. Therefore, it would have less kinetic energy.... with conservation of energy, kinetic energy = elastic potential energy or m*v^2=k*A^2 (spring constant is k, A is amplitude). Anyway, the gist of it is that the amplitude would be smaller. The spring constant would also be a factor, because A= F/k ... the greater the spring constant, the smaller the movement. By the way, all of this is theoretical/ideal.

As far as the design goes, I'm not really certain how effective it would be; however, I'd assume that non-conservative forces like friction as well as things like absorption and stuff would make it at least marginally more difficult to bump. If you could manage to make it such that the movement of the pin is less than required to make it pass the sheer line, you're all set, I suppose. A more forceful blow to the bump key or a difference in its shape/slope may counter this... Also, you must consider how hard you'd be willing to make it to insert the legitimate key.

Totally worth exploring the idea.

ps: Hi everyone, I'm new here.

[d_goldsmith]

What you propose is basically a master keyed system, which I believe is relatively easy to bump, easier to pick anyways. I'm not sure a heavier metal would work, it would make it more difficult, but not impossible.

The middle pins rest at the shearline in his idea, so it's not like a master.

[nezumi]

here's something I was considering...

What if you removed the top pin and spring and had a bottom pin that would lock the cylinder if pushed up at all and wouldn't fit outside of the cylinder? It would basically be a dummy pin. When picking it, it wouldn't have any pressure and you'd simply have to NOT hit it to unlock the lock (with the rest of the pins being real). As soon as you bump it, it moves up, blocking the shear line. If the order of the pins is such that it isn't last, it should block bumping.

I know there's something fundamental that I'm missing for such an obvious ruse (like you could just notch your bump key so it doesn't hit that pin, but then you'd need a separate bump key for each possible configuration).

Related, would having a second set of pins coming from the side of the lock help against bumping? Or is it possible to bump two directions at once?

[Mutzy]

having an extra pin above the top pin would squish the spring more and end in less spring tension (but after a period of time). It would only hinder, not stop.

[hippy5749]

Yes it is possible to bump in more that one direction at the same time. I can't remember which video I seen, but I'm Fairly sure Barry Wels bumped a lock that had top pins and side pins. I may be mistaken , but I don't see why not.....

[SnowyBoy]

Instead of a spring, could the chambers not be filled with some sort of high endurance foam?

Like a spongey type of material, which compresses the same way a spring does when the key is inserted and operated normally, but if an attempt is made to bump it, the foam will absorb the shock.

Obviously the foam material would have to be very robust and have an extremely long lifetime to match a spring, but i'm sure in the 21st century we have such a meterial.

Or another idea, would be based on a shock absorber for a car, oil filled chamber with a spring, so any shock from bumping will be absorbed by the fluid. Having the pins on the bottom of the lock would ensure the chambers stay filledwith oil for much longer than if they were on the top, where they could be surceptable to leakage by gravity.

I'm new to the whole bumping/picking thing, so my ideas might not be logical, but i have a good mental image of how it would/could work

[mrdan]

Instead of a spring, could the chambers not be filled with some sort of high endurance foam?

Like a spongey type of material, which compresses the same way a spring does when the key is inserted and operated normally, but if an attempt is made to bump it, the foam will absorb the shock.

Obviously the foam material would have to be very robust and have an extremely long lifetime to match a spring, but i'm sure in the 21st century we have such a meterial.

Or another idea, would be based on a shock absorber for a car, oil filled chamber with a spring, so any shock from bumping will be absorbed by the fluid. Having the pins on the bottom of the lock would ensure the chambers stay filledwith oil for much longer than if they were on the top, where they could be surceptable to leakage by gravity.

I'm new to the whole bumping/picking thing, so my ideas might not be logical, but i have a good mental image of how it would/could work

I think this would have to be in the manufacuring end maybe, but what about somehow Air pressure and using air as the "spring" or maybe some sort of small balloon type thingy that way you get the spring type tension but you could ramp up the pressure enough that it allows for pin movement but bouncing might be lessened. Or maybe that goo that is in the "Stretch Arm-Strong" toy you could make a slower moving yet compressable kind of stuff that the key would feel kinda weird putting it in but you might have a harder time bumping. Just a thought.

[SnowyBoy]

Instead of a spring, could the chambers not be filled with some sort of high endurance foam?

Like a spongey type of material, which compresses the same way a spring does when the key is inserted and operated normally, but if an attempt is made to bump it, the foam will absorb the shock.

Obviously the foam material would have to be very robust and have an extremely long lifetime to match a spring, but i'm sure in the 21st century we have such a meterial.

Or another idea, would be based on a shock absorber for a car, oil filled chamber with a spring, so any shock from bumping will be absorbed by the fluid. Having the pins on the bottom of the lock would ensure the chambers stay filledwith oil for much longer than if they were on the top, where they could be surceptable to leakage by gravity.

I'm new to the whole bumping/picking thing, so my ideas might not be logical, but i have a good mental image of how it would/could work

I think this would have to be in the manufacuring end maybe, but what about somehow Air pressure and using air as the "spring" or maybe some sort of small balloon type thingy that way you get the spring type tension but you could ramp up the pressure enough that it allows for pin movement but bouncing might be lessened. Or maybe that goo that is in the "Stretch Arm-Strong" toy you could make a slower moving yet compressable kind of stuff that the key would feel kinda weird putting it in but you might have a harder time bumping. Just a thought.

The goo in stretch armstrong (and stress balls) could be an idea. Although i think having the air idea wouldn't be reliable as you won't get a good enough seal to stop it leaking.

It all revolves around having a material that compresses easily when operated normally, but if shocked, it would be the same as smacking your hand on water really fast, thhe water will resist your hand for a split second. But if you put your hand into water slowly, there is no resistance.

[Johnny P]

In existing locks, just cut your current key to a depth deeper than the deepest depth of the known keyway.

For instance, the Schlage lock deepest cut by manufacturer is a 9 depth. Increase 1 or 2 bittings in depth to 9 plus .004 (for instance.)

This way, when you use the proper key, it will work, but bump keys which are cut to all 9s will not because they will raise the bottom pin above the shear line. I have done this for several of my customers.

[Mr. Wire]

There is a sure fire way to stop key bumping, purchase high security locks.

[hippy5749]

Depending on the high security lock, they can be bumped too! According to all I've been reading, there are very few locks that haven't been bumped yet. Plus, I think they are trying to find an easy way to modify existing locks to stop or dramatically hinder bumping. That way it would probably be affordable and very marketable for the inventor.....

[d_goldsmith]

If anyone wants to play with the foam idea, you can get a free sample of space foam from tempurpedic.

Clicky

[lokkju]

First off, very nice illustration
If you used a metal that could be magnetized for both top and bottom pins you might be able to prevent it. Thats the only thing I can think of that you could just "drop in" without modification. Of course you have to mill the new pins.

P.S. since we usually use some kind of steel for our picks it could also make it a real pain to try to pick magnetized pins. As far as the physics or magnetics I'm talking out my arse, but I can't really see why that might not be a solution. Add a oppositely charged "top pin cover thingy" that repels your top pin and it might work better.

This seems like the most workable idea I have seen yet... the main thing would be making sure the attractive force between the pins is enough to keep them from bein seperated by a bump - but this idea should work, and it would only have to involve replacement of the pins

[d_goldsmith]

I've heard that temperatures can effect magnetism. Also, you could make something that would change the magnetism of the pins and possibly make them seperate via that magnetism. Pins are currently made from Brass I think? As far as I know brass is not magnetic.