Sat Nov 14, 2015 5:15 pm by ckc123
Same comments I made on another forum for this lock..
their statement about the oversetting of the pins and "falling" is not correct.
if you look at the design of the inner cylinder, when the key is not in the vertical position, yes they are over set.. but that's irrelevant since the key won't line up with the slot to put tension on the core..
NOW.. once you put the key vertically, yes they do fall.. BUT.. you still can't open the lock (even normally) when you first get to the vertical position. you have to push it in. when you push it in, the pins are in the same position as a regular pin lock.. they are DOWN.. (not up. ans they have already fallen).
if you create a bump key with the deepest cuts, and rotate the key vertically, (but not pushed in), then all the pins are DOWN and can be bumped like a regular lock (but you can't tension it.. since the back of the key is not in the slot..) the "anti-bumping" is not the pins.. it's the way the key has to fit into the back slot to put tension on the core..
and in fact.. I think this is a bad design, and here is why.. in regular bumping, there is no direct link between the tension on the core (rotation by hand) and the force of the hammer hitting the key..
but with this lock, if you think about it.. there is a direct link.. as the key is forced backwards by the "bump" it gets forced into the back slot, and it's 100% consistent. The distance is always the same and it always slides in the slot the EXACT SAME TIME as the timing of the cuts on the KEY force the pins UP. you just need to find the angle to grind the back "flag??". to get the timing of the force on the back face to when the pins are above the shear line.
how you would exploit this is as follows.. if you file the back of the key (flag part the slots into the back face) at a 45-degree angle.. you now rotate the key a 1/2 to 2/3 of a key width to the same direction of the angle. when you push the key forward, (but not any rotation) .. that angle on the back of the key will automatically rotate the key for you the last few degrees.. (with the same timing every time). the challenge is now the bitting and the pins which are blocked ever so slightly by the "c" cut in the inner tube.. the distance here I'm talking about is 1/2 width of the key.. so it's simple.. reduce your key (where the bitting is) to half it's width.. so the core is in the fully rotated angle. (pins are now down) but the key is off by 1/2 a width, and the angle of the back grind if lined up exactly where you want it (1/2 way on the back 45 degree angle)
in their video they mention about the distance you need to push the key in that last step to get the "flag" in the slot, and it's not a full pin distance.. easy solution.. just offset the cuts in the key and bring them back the same distance of the flag to they are lined up with the fallen pins when the key is not pushed forward
now bump away..
ALSO I suspect the is a "denial of use" attack that can be done on this lock.. find a way to rotate the inner core ( with a paperclip/pick) with no key in it) to the vertical position.. the pins fall into the empty cut in the cylinder and prevent the inner core from being rotated any more.. you now can't get the key in the lock. just like when you rotate a picked core to 180 degrees and the pins fall into the bottom of the keyway.
the only way to prevent this is to have "angle" cuts on the inner core that would lift any dropped pins so it can rotate.. BUT.. that angled cut would make it even easier to bump as there is now extra space on either side of the keyway for the pins to drop for bumping.. if there is an angle cut, then there is no need to file the bitting to 1/2 the width, as the angle cut on the core wyou give you that extra space for the pins to drop.