High security locks such as the MUL-T-LOCK, are patented key-ways. They are issued to specific locksmiths or security companies. That is, only the company that provided you the keys can make copies of them because no one else in the region has access to the same key blank. High security keys are the best way to establish key control.
High security keyways are patent protected. This means that there is only one manufacture that can make the key. The manufacture then issues the specific key to a security or locksmith company.
High security door locks are made of the strongest material. Locks are heavier, screws are thicker, and they often contain other anti-theft measures. They are also bump proof locks. That is, there exist no key that can be used to bump the lock. When you give keys to employee, tenants, or homeowners in a complex, copy protection is a very real concern. In all of these situations, you don’t want keys made without your knowledge. There are two primary methods to prevent key copies from being made without your knowledge: stamping keys as “DND” (Do-Not-Duplicate) and using restricted keyways
Mul-t-Lock: Highest Security Locks and Keys
Restricted Keyways – Prevent Duplication – Affordable High Security