5 Common Lock Vulnerabilities and How to Protect Against Them

Locks are essential for security, but no lock is completely foolproof. As a locksmith with over 25 years of experience, I’ve seen firsthand how vulnerabilities in locks can be exploited. Whether you're securing your home, business, or valuables, understanding these weak points is crucial. In this article, I’ll walk you through five common lock vulnerabilities and how you can protect against them.

1. Lock Picking

The Problem:
Lock picking is one of the most well-known methods of bypassing a lock. Using simple tools like picks and tension wrenches, criminals can manipulate the pins inside a traditional pin tumbler lock to open it without a key. This method is often silent and leaves no visible signs of entry, making it a preferred technique for burglars.

How to Protect Against It:

• Use High-Security Locks – Invest in high-security locks from reputable brands like Medeco, Mul-T-Lock, or Schlage Primus. These locks have security pins (spool, serrated, or mushroom pins) that make picking extremely difficult.
• Consider Disc Detainer or Dimple Locks – These locks require specialized tools to pick, making them a less appealing target.
• Use a Secondary Lock – A well-placed deadbolt or additional locking mechanism can deter burglars from attempting to pick your locks.

2. Bumping

The Problem:
Lock bumping is a technique that involves using a specially cut key (a "bump key") to quickly and easily open pin tumbler locks. A quick tap or bump on the key transfers force to the lock pins, allowing the lock to turn as if the correct key was used. Like lock picking, bumping leaves little evidence of forced entry.

How to Protect Against It:

• Install Bump-Proof or Bump-Resistant Locks – Many modern locks come with anti-bump technology, such as sidebar locking systems or internal pin variations that prevent movement from a bump key.
• Use a Smart Lock – Electronic locks that don’t use traditional keyways eliminate the risk of bumping altogether.
• Upgrade to a Restricted Keyway System – Locks with restricted keyways prevent unauthorized duplication of keys, reducing the chances of a criminal obtaining a bump key that fits your lock.

3. Drilling

The Problem:
Drilling is a brute-force attack where a burglar uses a drill to destroy the pins or shear line of a lock cylinder, allowing it to turn freely. Standard pin tumbler locks are particularly vulnerable to this method, and it’s often a quick and effective way for criminals to gain entry.

How to Protect Against It:

• Choose a Lock with Anti-Drill Features – High-security locks often contain hardened steel pins or plates that prevent drill bits from penetrating the lock cylinder.
• Reinforce the Strike Plate and Door Frame – Even if a lock withstands drilling, a weak strike plate or door frame can be another point of entry. Reinforcing these areas with heavy-duty materials improves overall security.
• Install a Lock Guard or Security Plate – A metal security plate covering the lock cylinder can make it difficult for burglars to position a drill properly.

4. Shimming and Bypassing

The Problem:
Some locks, particularly cheaper padlocks and deadbolts, can be bypassed using shims or other tools. This method doesn’t attack the locking mechanism itself but instead manipulates the latch or actuator to open the lock. In some cases, criminals use thin plastic cards (like credit cards) to slide open simple spring-latch locks.

How to Protect Against It:

• Use Deadbolts Instead of Spring Latches – Spring-latch locks are particularly vulnerable to credit card bypassing, while deadbolts require the key to retract.
• Upgrade to a Padlock with a Guarded Shackle – Some padlocks have exposed shackles that are easy to shim. A high-quality padlock with a fully guarded or shrouded shackle reduces this risk.
• Ensure Proper Installation – A lock installed with too much gap between the door and the frame makes it easier to bypass with tools. Adjusting the strike plate and ensuring a tight fit can prevent this.

5. Key Duplication and Impressioning

The Problem:
Key duplication is an often-overlooked security vulnerability. If someone has unauthorized access to your key, they can easily make a copy at a hardware store or locksmith shop. Impressioning is another method, where a criminal creates a working key by using a blank key and a series of subtle markings to determine the cuts.

How to Protect Against It:

• Use a Restricted Keyway System – High-security locks often come with keys that can only be copied by the manufacturer or authorized locksmiths with proper documentation.
• Keep Your Keys Secure – Avoid leaving keys unattended in public areas, and be cautious about who has access to them.
• Switch to a Keyless Entry System – Digital and smart locks eliminate the risk of key duplication entirely.

Final Thoughts

Locks are only as strong as their weakest points, and understanding these vulnerabilities is the first step toward improving your security. By investing in high-security locks, using multiple layers of defense, and practicing good key management, you can significantly reduce the risk of a break-in.

At KeyZoo Locksmiths, we specialize in installing high-security locks to keep your home and business safe. If you’re concerned about your locks' security, feel free to contact us for a professional assessment and recommendations tailored to your needs.

Stay safe, stay secure!