Older garage doors, driveway gates and parking barriers may use fixed-code radio frequency (RF) systems that transmit the same digital signal every time they open. That signal can potentially be captured with inexpensive RF equipment and replayed later to gain unauthorized access. Check the age and model of your gate or garage-door opener and ask your installer whether it uses fixed-code, rolling-code or encrypted technology. If it relies on an older fixed-code system, consider upgrading rather than assuming a functioning remote means the system is secure. Also remove or disable lost remotes promptly and periodically review who has active access.