Key Control: Managing Duplication and Access
Key control is the policy and mechanics behind who can obtain, duplicate, and use keys in a facility. It protects bitting secrecy, limits blank availability, and defines privilege levels in master key systems.
Mechanical strength alone fails when anyone can walk into a mall kiosk and duplicate a "do not duplicate" key. Real control combines restricted profiles, contractual duplication channels, and inventory discipline.
Duplication Controls
High-security systems require factory or authorized-dealer cutters with security cards or online authorization databases. Machines refuse arbitrary bittings when cards are missing. Locksmiths maintain signing records for corporate accounts.
Do Not Duplicate Stamps
DND and DNC stamps are policy warnings, not legal barriers in most jurisdictions. Many locksmiths duplicate stamped keys when blanks exist — the stamp communicates owner intent, not enforceable law.
Restricted Keyways
Patented or uncommon key profiles reduce casual duplication. Locksmith associations distribute restricted blanks only to members. Skilled attackers can still mill blanks from photographs or impression a profile — control raises cost, not impossibility.
Security Cards
Manufacturer security cards accompany high-security key orders. Cards encode allowable bittings; without them, authorized cutters cannot originate keys. Loss of cards triggers rekey programs.
Operational Key Management
Key control extends to sign-out logs, sealed key rings, construction keying phases, and destruction of retired blanks. See high-security locks and master keying for hardware that supports control programs.