Ken's Locksmithery High Security Locks

The lock industry defines a high security lock cylinder as: a cylinder which offers a greater degree of resistance to any or all of the following: picking, bumping, impressioning, key duplication, drilling or other forms of forcible entry.

The secrets of operation, picking, bumping and impressioning pin tumbler cylinders are not really secrets anymore. You can find detailed instructions for the above defeat techniques on the internet.
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While some pin tumbler cylinders have the capability of at least 100,000 different combinations, only around 3,000 or so are actually used by most lock manufacturers for the keyed locks you can buy off the shelf. Since a particular brand of lock is usually very popular in a particular geographic area and the population usually exceeds 3,000...........................

Yes, most likely there are at least two houses or more that have the same key.
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