Rolling code technology is used in keyless entry systems, garage door openers for example, to prevent someone from stealing the code you use to open your garage door. Rolling code, called Intellicode by The Genie Company or CodeDodger by Overhead Door Company, replaces the old technology of setting dip switches on the garage door opener operator.
Dip switches were used back in the 1950′s through about the early 1970′s. This technology sent out a single code to open or close the garage. As garage door openers became more common, codes were often duplicated, as a set of dip switches can only have a maximum of 256 possible combinations. This caused quite a problem. Imagine driving down the street and being able to click your remote control and open your neighbors garage! What a security nightmare! Not only were there not enough variation of codes for the dip switches to handle, it was very easy for someone in the know to capture the signal, and use it at a later time to get into your home.
In the 1970′s the technology became more advanced.Instead of using a dip switch to control the security signal to open and close the garage door, a chip replaced it. This transmitter chip has the possibility to store about 1 trillion different codes. The code is generated using a random number generator. Each time the garage door remote is pressed the signal is sent and matched (or not) to the garage door opener. If the code matches, great! You are in! If not, the door will not open. Each time the remote control is used, a new code is generated and synched up with the garage door opener, hence the “rolling code” name. Capturing a code with this rolling code technology is also useless since the code is constantly changing. It is impossible to predict the code the transmitter will generate.
When looking at garage door openers, make sure it has the new rolling code technology, although, I am sure that 99% of the openers on the market today will have it. Also, if purchasing a home with an older operator in the garage, you may want to consider changing it to be sure it has the rolling code technology.