Lock Bumping – Bump Key Security Threat

February 2007:
Recently, the media has given a great deal of attention to “lock bumping”, a procedure that allows criminals to open many common door locks by simply inserting a specially modified key and tapping its end with a mallet or other tool. Along with the media reports, a number of warnings about lock bumping have been circulating via email and online.

The reports and warnings about lock bumping are genuine. Lock bumping, also known as “bump keying” and “key bumping” describes a technique in which an ordinary key can be filed so that, when it is inserted into a door lock and tapped, the internal pins can be jarred in such a way that the lock will open. The majority of pin-tumbler locks currently in use are vulnerable to lock bumping, including those normally found on people’s front doors. The technique is simple enough that, with the right knowledge, and a little practice, just about anybody could use it.

Unfortunately, the necessary knowledge is quite freely available on the Internet. There are a large number of easily accessible videos and tutorials that explain in exacting detail how to perform the technique. In fact, there are even sets of bump keys and lock bumping kits available for purchase.

Some observers have suggested that all the recent media attention about lock bumping could have the negative effect of making more criminals aware of the technique. However, a great deal of detailed information about lock bumping has been posted on the Internet for well over a year. Almost since its inception, the Internet has enabled the unscrupulous to access and share information about criminal activities and lock bumping is no exception. Therefore, it seems only fair that the general public are made aware of this potential security threat since many criminals are likely to be already well versed on the issue.

While lock bumping is certainly cause for concern, there is seemingly little law enforcement data available that details how often the technique is actually used in break and entry crimes. Since a lock that has been “bumped” is unlikely to be significantly damaged, police may have no way of telling if criminals have gained entry via lock bumping or some other means. FBI statistics from 2004 reveal that 32.4 percent of burglaries were classified simply as “illegal entries” in that no force was known to be used to gain access. In many of these cases, thieves may have entered via unlocked doors or windows, used unauthorized duplicate keys, or used other lock picking techniques. However, it is possible that lock bumping was used in at least some of these cases, although there is no concrete data to support this possibility.

Lock bumping will only work if the “bump key” used is designed to fit in the targeted type of lock. And if the key is filed incorrectly, it may not enter the target lock or may become stuck in the keyway. Of course, many criminals would already be skilled enough to rapidly and silently pick locks without the need to file keys or tap noisily on doors.

Thankfully there are locks available that are claimed to be “bump proof”, although they are significantly more expensive than normal locks.

YouTube: Lock Bumping and Bump Keys
Lock bumping: Wikipedia
Burglary – Crime in the United States 2004
Medeco Combats the Bump Key

Last updated: 28th February 2007
First published: 28th February 2007

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