Lock marketing sells features. However, only three things actually change how a door performs: how hard the cylinder is to attack, how hard the key is to copy, and how well the frame holds. Everything else is secondary.
Attack resistance
Standard pin cylinders can be picked by anyone who has practised, and bump keys defeat many in seconds. However, high-security cylinders add spool pins, sidebars and tighter tolerances, which makes picking impractical rather than merely difficult. Furthermore, hardened inserts resist drilling. Consequently on a front door this is worth paying for.
Copy resistance
This is the one most people underestimate. A standard key duplicates for a few dollars with no record, so you can never know how many exist. By contrast, restricted keyways require authorisation against a documented list. Therefore for a household where cleaners, contractors or tenants hold keys, copy control usually matters more than pick resistance.
Which to prioritise
If keys have circulated, choose copy control first. If the door is isolated and rarely overlooked, choose attack resistance first.
Smart credentials
Codes and fobs remove the physical key from daily use, and they revoke instantly. Consequently they solve the copy problem differently. However, nearly all retain a mechanical cylinder as backup, which is what an attacker would target. Therefore a smart lock with a builder-grade backup cylinder undoes much of the benefit.
Spending in the right order
Three-inch strike screws first, because most doors fail at the frame and the fix costs almost nothing. A Grade 2 deadbolt second. A high-security or restricted cylinder third. Smart credentials fourth, for convenience. Consequently spending in that order buys the most security per dollar, which is the opposite of how most people do it.
Questions we get about this
What should I upgrade first?
Strike screws. Because most doors fail at the frame rather than the lock.
Is high security worth it on a house?
On the front door, usually. Key control alone often justifies it.
Can someone copy my key?
With a standard keyway, yes, for a few dollars and no record.
Do smart locks replace good hardware?
No. The backup cylinder and the frame still matter.
What is bumping?
A technique using a specially cut key. High-security cylinders resist it.
