Rolling code technology is a security method used in keyless entry systems to prevent unauthorized access by generating a unique code each time the remote is activated. The technology is commonly used in automatic garage doors, vehicles, and other remote-controlled devices.
Rolling code systems operate through an algorithm that generates a new code, selected from billions of possibilities, each time the remote is used. Each code is valid for only a brief period, typically a few minutes.
When the remote sends a signal to the opener’s receiver, it includes the latest code generated by the algorithm. The opener then calculates the expected new code and compares it to the received code. If they match, access is granted, and the garage door opens or closes.
The garage door opener shares a secret signature with remote controls, keypads, and other keyless entry devices that were previously programmed. This signature allows the opener to identify the devices and compare the code it receives.
Rolling code technology and the secret signature-based algorithm make it nearly impossible to predict the next code which significantly reduces the likelihood of a replay attack.
A replay attack occurs when an attacker intercepts the code sent from the remote to the garage door opener, then tries to reuse it to gain unauthorized access. With rolling code technology, however, any intercepted code becomes invalid if replayed.
How Do You Know if You Have a Rolling Code Garage Door Opener
Most residential garage door openers started implementing rolling code technology since 1997.
For LiftMaster, Chamberlain, and Craftsman openers, rolling code technology (known as the Security+ 2.0 system) is available in models with a red, orange, purple, or yellow “learn” (or “smart”) button. Openers with a green button, manufactured before 1997, do not use rolling code technology.
For Genie garage door openers, rolling code technology (branded as Genie Intellicode) is available in models without dip switch technology, meaning they include a “learn” (or “smart”) programming button.
How to Reset and Program a Rolling Code Garage Door Opener
Resetting the codes on your garage door opener depends on the model. Generally, you can reset the opener’s codes by pressing and holding the learn (or smart) button for about 15 seconds. When pressed, the troubleshooting LED will light up or flash—continue holding until the LED turns off. At this point, any previous connections between your garage door opener and remote controls are erased.
To program a remote control, press the opener’s learn button once and release. When the troubleshooting LED is on or flashing, press your chosen button on the remote control, pressing and releasing consecutively until the opener clicks or the door activates.
For universal remotes, Marantec remotes, keypads, and vehicles, programming sequences may differ. Refer to the product’s manual or consult a licensed garage door repair company.
Can You Retrofit a Rolling Code System to an Older Garage Door Opener?
You can enable rolling code technology on an older garage door opener by installing an external receiver that uses rolling code technology. For added security, deactivate the opener’s original receiver if it doesn’t support rolling codes.
