Protect Yourself from the Bump Key

A Bump Key can unlock your door in seconds

My name is Dennis McEntire and I started a locksmith business because of the bump key. The bump key threat is a real problem to about 95% of the locks in America. In fact, I wrote a good portion of the text contained in the other bumping article mentioned here on eBay. The text was copied from a website run by a company called Citywide Locksmith, and that text from their website was copied from my website. They have permission to do so and have provided a link crediting me for the text.

Regardless of the source, the most important thing is that the public becomes informed of this problem. The lock industry and ALOA (the Associated Locksmiths of America) are burying the problem, stating that it does not happen and is not a real threat to existing locking systems. Unfortunately, that is not the case. Only recently has ALOA recognized the fact that the public has become aware of this problem through the media (television, magazine, newspaper, and seminars) and of course through the internet. Searching YouTube and virtually all other video sharing sites for the terms "Lock Bumping" yields many results, most of them videos of younger adults showing how it works.

Lock Picks

Bypassing locks, or more specifically, picking locks has been around for as long as locks have been around. We've all seen a scene in a movie where a thief pulls out a set of lockpicks and makes their way through a lock door. However, lockpicks are usually difficult to come by and take some skill and practice to use effectively. The real threat behind the bump key is that it takes very little skill, and can be learned by anyone who reads about it or sees a demonstration. What's more is that a bump key can be made from any existing key, cut or not. As an example, my very first bump key was made by filing down an old Kwikset key I had laying around the house. What was shocking to me at that time, and what is shocking to those that discover this problem for the first time, is how easy it is to do.

How a Standard Lock Works

I was just like most people years ago. I bought locks from my local hardware store, had keys that fit my lock and didn't fit a friends, and I felt safe. What I did not realize is that my locks, as well as millions of others, possessed a serious flaw, a flaw that was there from the start. Believe it or not, most locks these days are simple variations of Linus Yale's original Yale pin tumbler lock invented in the 1860's. That design uses a set of lower pins that contact a key, and are cut at different heights to match the key, and a set of top pins that contact the top of the pins. There are a set of springs that push the whole pin stack downwards.

When you insert the proper key, the bottom pins are lifted to the correct height, creating an even line where the top pins and bottom pins can separate, and you can turn the key. If even one pin is lifted too high or too low, the lock cylinder will not rotate. It seems like a good idea, but the bump key exploits a flaw in the design. The bump key simply transfers a force (by striking the key) into those pins, and makes them jump violently. The primary reason a bump key works is because those top pins and bottom pins separate for a fraction of a second, allowing a small window of time when the lock cylinder can be turned, effectively unlocking the lock.


The pin tumbler design can be found in deadbolts, knobs and levers, padlocks, post office mailboxes, mailboxes at your local mailbox rental location, and some cars. If the lock is a pin tumbler design and a matching bump key is possessed, most likely the lock can be opened in seconds.


The Bump Key is Very Effective

In my experience as a locksmith, I have determined that a lock has about a 95% chance of being opened with a bump key if the lock is less than 10 years old. Older locks will open with a bump key, but have to be lubricated first, which also takes seconds. The news stories about spraying WD-40 in the lock to prevent bumping are simply not true, it actually helps in the bumping process by freeing up sticky pins in the lock. I have personally seen a few of these stories, and have written a response to those TV stations about the mis-information.

Law Enforcement Needs to Know

I have also met with various law enforcement agencies about the bump key, and have asked each of the Detectives that I have met, "Have you gone to a burglary situation and have found no sign of forced entry?" They always say yes. This means one of three things: 1. The door was left unlocked, 2. The door was picked or bumped, or 3. Someone has a copy of the right key. Unfortunately it is very difficult to determine which method was used to open the door. The organizations that claim that lock bumping "is not a problem" cannot truthfully state that fact because there is really no way of knowing if a bump key was used or not, unless the thief is caught in the act.

I have said this in all the public speakings I have done: What scares me the most is that the bump key is very easy to use, and takes very little skill to master. Most of the videos on the internet are young adults showing how it's done. What's to stop them from "opening a neighbor's house" or "opening a friend's house" because it's so easy? Breaking and Entering is a felony, but in my mind that's not going to stop a young adult from doing it "just because it's fun and easy."

While I would agree that a high security lock probably won't stop a would-be thief that has targeted your property (unless you don't have any windows) it will stop the average teenager who is targeting properties randomly to open with a bump key.

Better Locks Around the World

In Europe and generally the rest of the world, there are hundreds of different types of locks available. Having so many locks to choose from makes it more difficult to have the right bump key. What's interesting about this is that in America the manufacturers have decided to make things simple for us: Use one of two different key shapes. Basically, all of the locks available in the hardware stores will use either a Kwikset (KW1) key or a Schlage (SC1) key. The key head shapes may be different, but the "key profile" is the same. A good example of this is Baldwin. The Baldwin keys have an octagon shaped large head, but the key itself is the same profile as the Schlage SC1 key. What this means is that an SC1 bump key will open Baldwin locks as well as Schlage locks.

Lock Quality Sometimes Makes a Difference

I have heard people say, "Oh, I don't have to worry about the bump key because I have a DEADBOLT on my door." Well, as it turns out, deadbolts open easier than knobs and levers because they are machined to tighter tolerances and are generally more durable than knobs and levers. What this means to bumping is that the energy transfer process is more effective. This applies also to more expensive locks. When a lock is machined to tighter tolerances, there is less room for slop in the locking system. Again, this means the energy transfer in the bumping process is more effective because there is less "wasted" energy when a lock is bumped open. If a lock is poorly made it is usually more difficult to open, simply because the energy is not directed as efficiently as the pins, and tends to move things around more inside the lock if there is more room for parts to move around. It's ironic that the more expensive locks bump open easier than the cheap ones. I bought a brand new Baldwin lock from a local hardware store and it bumped open very easy. The most difficult deadbolt to bump open out of a group of locks was the $8 Walmart deadbolt. It bumped open twice, and fell apart on the third attempt.

What You Can Do About It

It's not important that you fully understand the concepts outlined above. What you need to know is that the problem exists. What I have been doing with the media, news articles, public speaking apperances, my website, and the internet in general has been to inform the public about the problem and giving them the option of doing something about it. I've had criticism from some saying that I am talking about this because I want to sell better locks. I started my business because I wanted people to be able to get better locks without a lot of hassle. The first thing I did when I learned about the bump key was to hop on eBay and find a good lock. There are several eBay sellers now selling good high security locks at very reasonable prices.

My Take on High Security Locks

I would like to offer my take on high security locks and share my experiences with them. Some or most of these locks you may have never heard of, but they do exist and are sold on eBay at times. I have personally bumped open hundreds of different types of locks, and have been in contact with Barry Wels and Marc Tobias regarding the bumping issue and their experiences. Barry Wels runs a locksport website in the Netherlands and Marc Tobias is an Investigative Locksmith Expert and has been a big proponent of getting the bump key information into the right hands.

The best locking system in my opinion is the Abloy Protec system. This lock uses a series of 11 rotating discs. When the proper key is inserted the discs are each rotated at just the proper amount, and if all the discs are lined up in the correct position a bar drops into slots cut into each disc and the lock opens. The design is similar to a bank vault. The Abloy products are manufactured in Finland.

Medeco has been touted as a very good lock to prevent the bump key from opening your door. The Medeco system has been around since the sixties, and is under constant improvement by the company. Their high security element uses rotating bottom pins. If you look at a Medeco key from the top, you will see that the key's cuts are at angles. Those angles must match the appropriate pins in the lock in order for the lock to open. Older Medeco systems use 3 angles per pin, and newer "biaxial" systems have six angles per pin. The M3 system is Medeco's newest system and was created in order to extend the patent on the key blanks, in essence allowing Medeco and it's locksmiths to control key duplication. Medeco manufactures their products at their factory in Salem, Virginia.


BiLock is an Australian company making a unique high security lock. Their products appear on eBay from time to time, and are completely bump-proof. Their lock design uses a unique u-shaped double blade key, and no "top pins" that the bump key exploits. The BiLock products are generally lower priced than the other products.


Mul-T-Lock is a popular choice among those looking to upgrade their locks to a high security solution. There is one flaw you need to be made aware of. The design uses a "pin in pin" solution and a special dimple cut key. Since the design is still a pin tumbler design, it is actually still susceptible to lock bumping. I have personally confirmed this myself with several different Mul-T-Lock cylinders. The one saving grace is that the special Mul-T-Lock bump key is harder to obtain, since it must be cut by a Mul-T-Lock locksmith that would run the risk of losing their contract if they were caught cutting bump keys on their machine. However, I found a person on eBay selling Mul-T-Lock products and contacted them about cutting a bump key. I did not present myself as a licensed locksmith or anyone other than just a regular guy interested in a special product. Fifteen dollars and one week later I had a set of 3 Mul-T-Lock bump keys in my possession.

Schlage Primus is sometimes touted in the media as a good solution to the lock bumping problem. The design uses a special side milled key that lifts a set of "finger pins" to the correct height and angle. I am in the process of obtaining Primus keys and cylinders to do my own bump testing. I feel that the lock would bump open, but only with the correct side milling on the key. If a thief wanted to open any lock sold by a particular locksmith, all they would have to do is go to the business and buy a Primus cylinder from them and a bunch of keys. At that point they would have the correct side milling for locks sold by that locksmith. Sometimes locksmiths do not buy the complete Primus program (thousands of dollars) and simply sell the "nationally available" side milling available to any locksmith. One of those bump keys could potentially open Primus locks all over America. As I mentioned, I have not been able to confirm or deny that the Primus cylinders are safe from the bump key.

High Security Locks that are Bumpable

Scorpion CX-5, the Assa Twin and similar products, the Schlage Everest, some of the Kaba dimple key products, most DOM locks, and the Marks USA High Security Line are all vulnerable to the bump key if the bump key has the right side milling on it. Again, obtaining the right side milling might be a matter of just going to the store and buying one of their locks and several keys. It's safer than the average lock but still something to keep in mind.

I hope this information has proved useful to you, and that it allows you to make an informed decision as to what you should do about the bump key problem. The eBay rules state that I cannot post my contact information here or any links to my website, but I appreciate you taking the time to read this article and hope that my information is useful to you.