Master key

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Video clip showing a lock.

Typical tools.

A master key is a specialized tool used to open locks without using a key or breaking a lock.

The manufacturer of the first "professional" master key was the American inventor Alfred Hobbs, who received several patents on his master keys and in 1851 founded the company Hobbs Hart & Co. Ltd trading in lock picks ^[1] .

Lock picks can be used to break locks by criminals. According to the “Forensic Encyclopedia” of R. S. Belkin, master keys can be classified by the type of locks for which they are intended to be cracked (cylinder, level, spring); the principle of operation of each type of master key is somewhat different ^[2] . Ustiti (a term from the thieves' jargon, derived from the English name for the marmoset - the genus of small South American monkeys), which is a handicraft tool similar to tongs and designed to grab the tip of a key left in an inside of a door lock, can also be used to break locks ^[3] . S. I. Potashnik in the work “Forensic investigation of locks” distinguishes uystiti as a separate type of device for opening locks that is different from a master key ^[4] .

At the same time, master keys can be used, for example, by locksmiths in the event of a lock or key breakdown or a key loss. In addition, sometimes opening your own locks with master keys can be a hobby or even a kind of sport, with the presence of “interest groups” ^[5] .

The attitude to master keys and their use in different historical and modern states is different, but mostly negative. For example, in the Brazilian Empire, it was considered unlawful to store or sell any items that could be regarded as hacked ^{[6] [ significance of fact? ]} . In some states - for example, in Great Britain ^[7] , and Japan - even the storage of master keys is actually prohibited.