Overlift Attack - What is it?

[Theist17]

I've heard the phrase used before, but I'm not entirely sure what it is.

Am I right in thinking that it is an attack by which the entire pin stack is lifted above the shear line? If so, why isn't this the preferred method? It seems like the height of a fully compressed spring and pin stack would prevent the rotation of the lock. Or is it something else, like lifting the pins so that it frees another stack in the plug?

If this is something which applies only to certain high-security locks, I totally understand if y'all aren't comfortable letting me know.

[weilawei]

The entire pin stack is lifted above the shear line (typically with a comb pick), forcing them into the bible. This can be destructive, potentially popping the cover off the top. Balanced pin-stacks are used to prevent the entire stack from being pushed into the top, though it won't prevent the cover from popping off.

[Solomon]

weilawei knocked it on the head. We don't really go for this method as hobbyists for obvious reasons, but in terms of just getting a lock open it's mainly down to their unreliablity. A lock doesn't need balanced pin stacks to stop comb picks in their tracks, longer key pins in general will do the trick but it really depends on the lock.

Regardless, the commercially available ones are junk and can only deal with the most basic of keyways so their use is restricted mostly to cheap padlocks. The only locks they work on are complete junk and can be opened just as quickly by picking or, in the case of padlocks, other bypass methods. I've seen them used very effectively, and on some pretty serious locks... but it's not as reliable a technique as it was, say, 30 years ago.

[pin_pusher]

"comb picks" are designed specifically for this purpose. basically works on some locks, doesn't on others. a basic design just measured from the spacing between pins and the height of the plug. almost positive there is a topic here that shows a video. (no luck finding it)

[Rickthepick]

Its not all about comb picks,
overlifting also refers to a method where all pins/levers are dropped to the sheer line as opposed to lifted up.
works well on cheap 3 and 5 lever locks

[raimundo]

Over lifting seems to have been very popular with the british members here so answers from people in the UK would probably be the ones to listen to.

[weilawei]

Good point rickthepick. illusion mentions this in his lever lock tutorial:

Overlifting

Now the previous method will allow you to open them quickly and reliably, but there is another method – it is called overlifting and it essentially involves using a pick big enough to lift all the levers at the same time, and merely lifting them upwards whilst applying tension – with the first 2 levers having no fence on the bottom of the lever then they merely need to be lifted to the maximum height to be in position, the 3rd lever does have a fence on the bottom of the lever and it is to prevent overlifting – to overcome this simply lower the 3 levers whilst applying medium tension, the last lever will align itself and the lock will open. This method is less effective on locks with anti-picking notches, and will take more skill, however on a 3 lever sash-lock with no security features it is devastating.

Here is an example of an over-lifter for a 2+3 lever lock which is commercially available:
(This can be improvised easily with standard wire)

[illusion]

Not really much to add really - I've had a fair amount of success against locks with quite open keyways using a comb pick, although it's worth pointing out that often locks with such keyways are often easy to pick anyway thus making it more of a neat trick than anything.

I often overlift the pins when picking - lift them up high and then lower the pins to catch the sheer line as they come down - tends to avoid the antipick notches on the top pins but obviously it's less useful with serrated bottom pins, especially if the plug is also counter-milled. Good tension control makes this technique more effective, and 'bouncing' the wrench gently with your finger tends to help I find.

Overlifting lever locks as said is very effective against 2 & 3 lever locks, although it also worked to open an ERA 5 lever, uncurtained lock when I last tried it. The trick is to apply a lot of tension to bind the levers at first then keep lifting and lowering the levers whilst changing the amount of turning force every 10 seconds or so until the lock opens.