[Free] Decoding Common Combination Locks

Understand the security level of different, common combination locks by learning to decode them. – Free Course

Added on March 7, 2025 Business 2 min read

What you’ll learn

Decode common digilocks without tools.
Decode common key boxes without tools.
Use a notched decoder technique to decode rotary wheeled key boxes.
Evaluate the security of various common key boxes.
Understand where combination locks should and should not be used.

Requirements

Beginner level. No experience needed.
To follow along, you'll need the locks in question.
For the rotary wheeled (Master Lock) key box, you may want a notched decoder or you can make / buy one.
For the other keypad based locks, you'll just need fingers and some persistence to learn the techniques.

Description

This is a simple introductory course to decoding techniques for three common types of combination lock.

By understanding the methods by which these can be bypassed, you will understand better the application for these systems. It is often said that the Master Lock key safes are really easily opened with simple tools, but is it really that easy and is a domestic burglar really going to go that far? What about the tools? Similarly, digilocks are seen everywhere costing anywhere from £30-£250, but are they as secure as the price suggests? How long does it really take to decode them?

We are told the strengths of a product, but we also need to understand the weaknesses to use them properly.

The criminals already know about these techniques – they aren’t secret. The public need to understand the techniques to get an idea of who will use them. Lockpicking Lawyer and his ilk make this look so very easy but you’ll only understand how easy it is when you come to try it yourself. You may go from thinking Master Lock key boxes are a scourge to understanding there is a place and a correct application for everything.

These are instructional videos and guides, not skills demonstrations, which is what differentiates this course from the YouTube style videos. I’m not here to show off, but to teach.

When you’re done, you’ll be able to evaluate where specific locks should be used and have a greater understanding of their real-world security.

Author(s): Phil Smith