Lock picking is the art of unlocking a lock without its intended key. Locksmiths are trained in lock picking. The tools for lock picking are usually different for each type of lock and can sometimes be improvised from common items, such as hair pins or safety pins. Some people enjoy picking locks because it has hack value and doing so is fun to them.
Usually it is possible to bypass a lock without picking it. Most common locks can be quickly and easily opened using a drill, bolt cutters, or a hydraulic jack, or the hasp, door, or fixture they are attached to can be cut or broken. A lock that offers high resistance to picking does not necessarily make unauthorized access more difficult, but it will make surreptitious unauthorized access more difficult. Locks are often used in combination with alarms to provide layered security.
Techniques to pick different types of locks
A tension wrench (or torque wrench) is used to apply a torque to the cylinder, while a lock pick (or picklock) is used to push individual pins up until they are flush with the shear line. As each pin is manipulated to its correct height, the cylinder will turn fractionally causing another pin to bind. The pins will not bind simultaneously because they will not be aligned perfectly with the axis of the cylinder. Once all of the pins are flush with the shear line, the tension wrench can be turned fully to open the lock.
Raking or scrubbing a pin tumbler lock is usually done before individual pins are pushed up. While applying torque with the tension wrench, a lock pick with a wide tip is placed at the back of the lock and quickly slid outwards with upward pressure so all the pins are pushed up. Raking may allow some of the pins to be flush with the shear line and can make the job easier.
Some pin tumbler locks have special pins, with serrations, mushroom heads, or spool shapes, that make lock picking more difficult by causing the pins to bind in locations other than their correct ones.
Another technique, often the fastest, uses a vibration pick or gun, which sharply strikes all the bottom pins simultaneously while light torque is applied; like a cue ball, the energy is transmitted through to the top pins, which fly to the top of their well. This momentarily creates a large space between the two pins.
To defend against these attacks, high-security locks use a sidebar, which engages from another axis and also prevents the lock from turning. Medeco does this by requiring the pins to be rotated to a correct position, as well as moved to their correct height. Other brands put the sidebar cuts in the side of the key.
Pin tumbler locks are sometimes arranged in groups, where each lock in the group can be opened by either a master key, which will open any lock in the group, or a specific change key, which will open only that one lock. This is done by using pins with more than two parts, so that it will shear at more than one position. In poorly supervised areas, those who have access to a door which is unlocked or for which they have a legitimate key can remove the lock from the door and disassemble it to determine the master keying pattern.
A tubular lock pick is used to keep the pins from moving once they have been picked until all have been picked. These locks can be picked using a pin and a torsion tool, but using this method is very much slower than using a tubular lock pick, and for many locks the process has to be repeated up to four times to open the lock.
A double-sided pick can be used to keep the discs from moving once they have been picked until all have been picked.
Cheap combination padlocks can be opened using a thin metal piece slid between the body and shackle. More expensive ones require the lock-picker to find the combination to the lock. The exact technique to do can differ and some manufacturers, such as Master Lock, make this process very time-consuming on their latest models.
With a warded pick, warded locks are probably one of the locks easiest to pick. Warded picks have basic shapes that fit many types of warded locks. They are inserted into the key hole and slowly turned until the lock opens.
Car locks can sometimes be opened by slipping a metal ruler that has had its end cut into a hook shape (a slim Jim), down the front of a car window (in between the rubber). The ruler is manipulated until the lock cable is caught on the hook. Pulling the cable up will open the door.
- MIT guide to lock-picking (http://www.lysator.liu.se/mit-guide/mit-guide.html) by 'Ted the Tool'
- Lock Picking 101 (http://www.lockpicking101.com/index.php) Discussion Forum on and about Lock Picking
- FAQalt (http://www.indra.com/archives/alt-locksmithing/).locksmithing Frequently Asked Questions
- How lock-picking works (http://people.howstuffworks.com/lock-picking.htm) at Howstuffworks.com