Tom has 17 years of experience as a commercial locksmith and over 20 years in door hardware distribution.
What Is Key Bumping?
Key bumping is a means of simple entry that requires little skill. A general rule of thumb, the cheaper the lock, the easier it is probably going to be to bump. Therefore, you tend to get what you pay for when shopping for a bump-resistant lock. Following are strategies you can use to inhibit or defeat key bumping.
Key Bumping Video
Most Effective: Get a Totally Keyless Lock
Some mechanical or electronic locks do not use a key at all and, therefore, are completely immune to key bumping. The most secure example would be the Kaba Mas CDX-09 which uses a dial outside like a safe lock. Sargent and Greenleaf offers the "Brute" mechanical rim lock to compete with the CDX-09. The CDX-09 is an electronic lock that generates its own power, used widely in federal government applications. Much cheaper are the Kaba Ilco 900, 6200, and 7100 series locks.
Security professionals know that anything that is put on with tools can be taken off with tools, but as far as key bumping goes, these locks offer no opportunity.
Effective: Get a Pick-Resistant Lock
Pick-resistant locks have an extra set of tumblers or locking apparatus so that, in effect, the key has to do two things at once. Because of their resistance to manipulation, these locks are also resistant to key bumping.
One of the most popular pick-resistant locks is the Medeco. The pin tumblers in this lock must not only be raised to a certain level, they must be turned right or left or not turned at all in order to allow the key to turn. An effective set of bump keys would need to have several thousand variations of angles in order to turn the pins properly so that they could be bumped.
Mul-T-Lock cylinders use a pin-within-a-pin principal. Since the keys are drilled to precise depths to operate the pin tumblers, bump keys would be exceedingly difficult to make.
Another popular pick-resistant lock is the Schlage Primus. This lock uses a second set of pins so that the key must do the job of 2 keys. This system is not quite as secure as the Medeco since the keys are similar within a geographical area. If a key bumper were to get the blank, they could conceivably make a bump key that would work.
This principle is similar to the one below. Both rely to an extent on luck.
Somewhat Effective: Get a Lock in an Uncommon Keyway
Shown in the illustration at right, is the part of a lock cylinder called the 'keyway.' The keyway is the shape of the hole that will accept the key.
One way to inhibit bumping is to get a lock with a keyway the key bumper is not likely to have. Bump keys must be the same keyway as the lock or they won't fit in. If they won't fit in the lock, they can't be used to bump the lock.
If you get an odd enough keyway, the key bumper would perhaps have to take a photo of your lock, identify the keyway, get a blank, and then return to bump your lock. All of this adds risk to the act of key bumping, providing more chances to be caught or identified.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: I have a Medeco lock on my front door. Someone is stalking me and lets me know they are going in my home. The strange thing is they lock all the locks back. Does this mean they have a copied key?
Answer: There are many things this could mean. The only thing you can do is to install a "nanny cam" and catch your stalker on tape. Then you'll have evidence you can take to the police.
Question: I am going thru the exact same thing with my stalker. They let me know they have been in my house by changing or takings things from me. I have tried securing cameras which become inoperative when they realize I have them. I have tried every lock on the market but nothing seems to work. Any further advice?
Answer: Try to conceal the cameras so the intruder does not discover them. Use low tech, motion activated cameras that are not connected to the Internet so they are harder to discover or hack.
If possible, also place cameras outside to record images of people approaching or leaving.
You can also hire someone to check your place at random times when you are out. This will make it more difficult for them to plan their incursions.
© 2008 Tom rubenoff
Tom rubenoff (author) from United States on June 15, 2020:
Hi Jo, I am not an expert on cameras, but what you are looking for is a standalone, battery-operated camera. The Bushnell Aggressor looks like an inexpensive and effective choice. It does not connect to the internet. The key will be securing the camera so it cannot be easily stolen or destroyed. Even if it is destroyed, the memory card may still survive. Good luck.
Jo Mouton on June 14, 2020:
I have neighbors that have had access to my house for over 17 years. I had to move out but still own the home. They have gained access to surveillance cameras as well as the alarm system. I’ve tried the Medico lock. (Drilled though it) My system is with AT&T. Also garage break-Ins! I’ve called the police but I have no proof that this is happening.
Can you provide me with the name of a low tech motion camera that is not connected to the internet?
JuneLadybug on April 06, 2020:
This is freaking ridiculous!!! Tom Rubenofff, it's a great article you wrote regarding some of the locks that cannot be bumped, regardless of some of the comments from other readers that the locks you mentioned have been bumped. I myself just as almost everyone who posted a comment am a victim of harrassment thru audio and video surveillance from a small group of neighbors who wait till were gone or asleep to enter our property. They are really good hackers and have broken my electronic devices of where I have or I should say HAD the evidence and have let me know they were inside our home. They have actually altered the electrical wiring in our home and gaslighting me to make me look as if I'm going nuts to my family. After reading comments on how the law has turned their blind eye to the reports of us, the "victims" it is disgusting to see how we have a corrupted PD all over the U.S. Too many crooked cops, that they give preference and obnoxious laws that protect the criminals. So corrupted it makes me sick to my stomach. But now I don't even want to report it Houston, Tx PD may believe I'm making this story and will probably ask why would I think these folks are keeping tabs on me thru surveillance and all. I'm so sorry for venting. Again, great article Tom, but I am probably going to design my own door lock. Lol
help on February 03, 2020:
how do I conbtact this author directly
Greg on January 29, 2020:
I have the same issue, being stalked, they are locking and unlocking Medaco deadbolt. Did catch them on video (no glow). Lawyer has the proof. Police will not help. Pin hole cam well hidden. Illegal Stazi style harassment of American citizens sanctioned by the government.
Bill the target on July 16, 2019:
Home has been entered and personal effects moved around. Two times front door was ajar when got home. Police have told me there is no evidence of crime, after 3rd call I was asked if I've had a 5150 for psychological examination. Locks changed 3 times, locksmith told me home depot grade locks are inadequate: rekeyed, bump pins and stiffer springs were installed. My home is locked up tight. If you follow a schedule and your neighbors are involved and or strangers are following, you can't protect yourself. I installed a home surveillance system and haven't seen anything, at least I can verify that close doors and locked.
Tom rubenoff (author) from United States on September 07, 2018:
Sounds like your assailant is a well-trained espionage agent. I suggest going more analog. Before you leave, lock all your doors and windows with padlocks or slide bolts from the inside except the one you will use to exit by. Then place stand alone motion activated cameras at strategic locations to capture their image. They make wildlife cameras that will do the job. When you get home, make sure to unlock all the slide bolts and padlocks so you can safely exit in the event of an emergency.
Stacy on September 06, 2018:
I am having the same problem with a psycho that won’t stop. She is constantly breaking into my home and the police in Columbus Ohio won’t arrest her because she uses a bump key. She is also a hacker so she disables my security cameras and alarm system. Any suggestions?
808 Locksmith on April 09, 2018:
Schlage has a keyway called Everest 29 that can be purchased without any excessive paperwork or expense as you would with a Primus or Medeco key system. The key is patented until the year 2029; is very secure, hard to acquire blanks (preventing bump keys) and overall a great choice for 90% of your home or business needs. Contact your local certified locksmith or a reputable online lock vendor for further assistance.
Salas on October 21, 2017:
I have been a constant target of some deranged, disturbed pervert! Just like Jeannette Martin stated the police use the poor excuse of no forced entry! All meanwhile we spend ridiculously amounts of money on "pick,bump,drill resistant high SECURITY grade 1 commercial locks! To secure our home and belongings! What is left behind is destroyed vandalized ! If anyone knows of a high security deadbolt or method of keeping my home 100% secure please do inform and educate me!..there has to be a solution.
jeannette martin on June 13, 2017:
I had the protect 2 deadbolt and they got through.....I thought I was secure. once in the house they found the key card and stole the extra keys......another waste of money. in south Florida we have locksmiths that bump locks, and like the protect2, picked. there is no security in this country.
Why don't you get yourself a lock without a keyway , meaning a round keyway . on May 26, 2017:
Yes you won't be able to pick it or even bump it there were no tumblers in the lock!
J. Martin on March 17, 2017:
try calling Medeco locks and ask them if their high security lock is bump and pick proof.....I was told that their locks are made so that if someone looses their keys that they can get in to their property. I have spent over $20,000 in deadbolts by well known locks, all were bypassed. Why don't lock manufacturers make secure locks......if you are not smart enough to have extra keys, why should I have my locks compromised. The locks that securely lock your house are made for government use......I need help. I invite any lock manufacturer to give me ( I will pay for it) a deadbolt lock that is secure from bumping or picking. The person that keeps getting in my house has stolen almost everything I own and the Ft. Lauderdale police department don't care because they don't see signs of forced entry. The FBI considers lock bumping as forced entry. We have a problem in this country and no one cares until someone bumps their locks. I had the alloy protect 2 installed, they picked the lock and then stole a copy of the key. (by far the best lock that I have used, but can be compromised.
jeannette martin on February 19, 2017:
The CDX-09 and 10 is sold to the government or high security places. It is very much conntrolled. If I could have that lock, I would have installed it.
jeannette martin on January 24, 2017:
had all 3 locks, all bumped. I need a secure lock. I don't have a secure house and the thief keeps coming in when I leave the house.
Klinger on March 14, 2015:
Einstein was a thief... But if you get a lock with a carved key then bumping is out of question ;-)
Tom rubenoff (author) from United States on April 16, 2014:
Okay, Einstein. Relay to us, pray tell, how to bump a CDX-09. Or tell me, buckaroo, how key bumping any lock that has no key is possible to do? 'Tis true that anything installed with tools can also be taken apart with tools. But to key-bump a lock that has no key would be impossible to do, even for you. :D
GottaBeABetterWay on April 16, 2014:
unfortunately, all those locks you mentioned have been bumped. :-/