High-security locks are mechanical locks that provide more security than standard locks by using more complicated and precise parts. These can include an extra set of pins as well as mechanisms that resist picking or drilling. In addition, the key blanks are a different shape than the standard blanks, so they cannot be obtained by normal means.
The process of controlling the distribution of keys in a system is sometimes referred to as “Key Control”. Keys in a standard system are easily copied by anyone who has access, from the company president down to a part-time cleaning person. Conscientious security managers will sometimes print “Do Not Duplicate” on the key, but this provides only a small defense and does not guarantee your key will not be duplicated. High security keys solve this by only allowing duplicates to authorized individuals.