Lock picking sounds like movie magic, but it's a real technique that any determined intruder can learn from YouTube in an afternoon. Understanding how it works is the first step to knowing how to defend against it.
Most residential locks use a pin tumbler mechanism. Inside are several spring-loaded pin stacks. When the correct key is inserted, it raises each pin to the exact height that aligns the gap between the driver pin and key pin at the shear line — allowing the cylinder to rotate and open.
A picker uses two tools: a tension wrench (to apply slight rotational pressure) and a pick (to manipulate pins). By applying tension and 'setting' each pin at the shear line one at a time — exploiting manufacturing tolerances — a skilled picker can open a standard lock in under 60 seconds.
High-security locks use spool or serrated driver pins that resist picking by creating a false set — the cylinder appears to have turned but actually hasn't. The picker must release tension and try again, making the process exponentially harder.
Bump keys are specially cut keys that exploit the spring-loaded nature of pin tumblers. A bump key is inserted and struck ('bumped') with a mallet, momentarily bouncing all pins to the shear line simultaneously. Standard locks are highly vulnerable. Security pins also defend against bumping.
Look for locks with documented pick resistance: Medeco uses rotating key pins and a sidebar. Abloy Protec2 uses disc detainers instead of pins — essentially immune to traditional picking. Mul-T-Lock uses a pin-within-a-pin system. All three use restricted keyways to prevent unauthorized key copying.