The first step toward learning to defeat locks is a thorough understanding of how they work, where their security comes from, and how their design and manufacture introduces potentially exploitable vulnerabilities. These imperfections are very small -- as little as .0001 inches in some cases -- but they are what allow us to manipulate ("pick") locks open without using the correct key. Picking depends on weaknesses in the implementation of locks -- small manufacturing imperfections -- rather than fundamental, abstract design flaws that would be present no matter how carefully made the locks might be. High-security locks often incorporate one or more secondary locking mechanisms beyond that provided by the conventional pin tumblers. Well, it’s all one cat: the whole cat moves. It’s an expanded present. Now that you can spot a pool and billiards table, it’s time to bring the fun home to stay! These balls are typically larger than those used for pool. It is not clear what some of these picks are intended to actually do. Special double-sided jiggle-rake picks are commercially available for such locks. Some pin tumbler locks incorporate "high security" features, including secondary locking mechanisms and features intended specifically to frustrate picking.

The basic design consists of a rotatable cylinder tube, called the plug, linked to the underlying locking mechanism. The plug/shell border is called the shear line. Note the border between the plug and shell, which forms the shear line, and the cuts in each pin stack resting within the plug. Right: With all of the cuts at the shear line, the plug can rotate freely within the shell. Pin tumbler lock picking consists of raising the cuts on each pin stack to the shear line, one by one, until the plug turns freely. A key that is bitted to the wrong depth in even one pin position will not operate the lock. In general, wafer lock picking employs the same techniques and tools as those used for pin tumbler locks. The numbers on the front of the practice locks indicate the keying codes, from the front-most pin stack to the rear-most. When a key is inserted into the keyway slot at the front of the plug, the pin stacks are raised within the plug and shell. He is currently teaching a course about making applications for Facebook that are engaging and persuasive. In addition to making picking more difficult, secondary locking mechanisms are sometimes also intended to make it more difficult to reproduce unauthorized copies of keys.

First count them, making sure you find all five (or six). Typical commercial and residential locks have five or six pin stacks (although four and seven aren't unheard of), with from four to ten distinct cut depths used on each. A detailed introduction to locks is well beyond the scope of this document; we assume here that you already understand, or have access to, the basic principles. Other classes of attack, not discussed here but at least as worthy of study and scrutiny, include lock decoding, which is concerned with producing a working key based only on access to the external interface of the lock, lock bypass, which aims to unlatch the underlying locking mechanism without operating the lock at all, and forced entry, which, as the term suggests, involves the destructive application of force to the lock or its surroundings. The term "billiards" refers to any game that is played on a cloth covered table with a cue stick.

See Figure 1. (In practice, the cuts are produced by stacking pin segments of particular lengths, not by actually cutting the pins; hence the term "pin stack.") With no key in the lock, all the pin stack cuts rest within the plug. But before we go into that, I just want to know if there are any questions; if I’ve made myself clear, and if there are any of you who find me utterly unintelligible? So then, there is practiced throughout the world-rather more in Asia than here, although always by a minority of people-a discipline called meditation, what is billiards which is to get in touch with reality. And I’m sorry that our facilities do not allow you to sit on the floor and to get sort of in the right relaxed, awake position. This is called a mokugyo, and it’s a sort of wooden drum which, as you heard, makes an extremely effective noise that can be heard for a very long way. You should be able to confidently find each pin and push it all the way up, without jamming the pick against anything or moving other pins.