[Boost-bugs] [Boost C++ Libraries] #8252: The Combination Lock ###

Subject: [Boost-bugs] [Boost C++ Libraries] #8252: The Combination Lock ###
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-03-06 02:17:41

#8252: The Combination Lock ###
------------------------------+---------------------------------------------
 Reporter:  abbarchancma1977  |        Type:  Bugs            
   Status:  new               |   Milestone:  To Be Determined
Component:  None              |     Version:  Boost 1.52.0    
 Severity:  Problem           |    Keywords:                  
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 A combination lock is a type of lock where a series of numbers or symbols
 can be used to open the lock. The series is generally a certain
 permutation rather than mixture. The sequence might be entered using a
 single rotating face which interacts with several discs or cameras, or by
 using a couple of several rotating discs with written numbers which
 specifically interact with the locking mechanism.

 Multiple-dial locks

 One of the simplest forms of combination lock, often used in low-security
 situations is the bike lock, which uses many revolving discs with notches
 cut in to them. The lock is secured by way of a pin with many teeth onto
 it which hook to the revolving discs. Once the notches in the disks
 arrange with tooth on the flag, the lock may be opened. This lock is known
 as to be among the least secure types of combination lock.

 Opening a lock without the combination is dependent upon the small
 irregularities in the machining of the elements. Until the lock is
 machined correctly, if the pin is drawn outward, one of many teeth can
 pull more strongly than the others on its corresponding disk. Until a
 click is heard, indicating that the tooth has settled in to the step this
 disk is then turned. The process is repeated for the remaining discs,
 resulting in a mixture, and an open lock, in hardly any time.

 Single-dial locks

 Mixture locks entirely on padlocks or safes might use an individual switch
 which interacts with several similar discs  Activity  or cameras.
 Typically, a lock with this type is opened by rotating the dial clockwise
 to the first numeral, counterclockwise to the 2nd, and so on within an
 alternating fashion before the last numeral is achieved. The cameras
 typically have an or notch, and when the right combination is joined, the
 notches arrange, allowing the latch to suit into them and open the lock.

 Mixture locks with this type are usually more reliable compared to
 multiple-dial lock, however many of these do have flaws. Like, early
 combination padlocks built by Master lock could be cracked by taking on
 the shackle of the lock and until it stopped; each numeral in the
 combination could be revealed in this manner turning the switch.

 More modern types of Master padlock with a 40-position face have a
 physical weakness that could hand out the last numeral in the combination,
 and the first two numbers have an exact relationship with the last number.
 That weakness reduces the number of possible combinations from 64,000 to
 only 100, which can be tried in a comparatively short timeframe.

 Affordable padlocks in many cases are vunerable to the usage of a padlock
 shim, which may be used to release the shackle without entering a mixture.

 Other kinds

 Many doors use mixture locks which require the consumer to enter a numeric
 sequence on a keyboard to facilitate entry. These special locks often
 involve the excess use of digital circuitry.

 The main advantage of this system is when useful for the doorway of a
 large company, each worker can be told the code number with out to offer a
 vital to each person.

 If the code number is identified by somebody out site the desired group or
 isn't changed regularly, it might allow comfortable access to a potential
 intruder the problem however, is.

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/8252>
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