lock is an integral part of every house. A man can have peace of mind only when
he has a proper mechanism to lock his house when he is away. At present mechanical
locks are being used. These locks have levers in them that are used to lock or
unlock the unit. Keys that have a particular pattern of cuts and notches on them
control these levers. Each lock opens only if the pattern of cuts and notches
inside it match with the pattern on the key.The main disadvantage of this mechanism
is that one cannot open the lock if one has lost or misplaced the key. The house
owner will be stranded outside his house if he loses the keys to his front door.
This conventional lock-and-key mechanism poses a lot of security problems too.
Any number of duplicate keys can be easily made from the original key. These duplicate
keys may be used for unauthorized access without the knowledge of the owner. Burglars
may find the right key to open the lock by trying different keys one after the
other from a bunch of keys. An expert thief doesn't even need a proper key to
open a lock. He can merely do it with a hairpin. If everything else fails, the
thief can physically break open the lock.