Piggybacking and Tailgating: Mantraps

A common and frustrating loophole in otherwise secure access control systems can be the ability of an unauthorized person to follow through a checkpoint behind an authorized person (called piggybacking when the authorized person is complicit — i.e., holds the door — or tailgating if the unauthorized person slips through undetected). The traditional solution is an airlock-style arrangement called a mantrap having doors at entry and exit, with room for only one person in the space between the doors. Mantraps can be designed with access control for both entry and exit, or for exit only — in which case a failed attempt to exit the enclosure causes the entry door to lock and an alert to be issued indicating that an intruder has been caught. A footstepdetecting floor can be added to confirm there is only one person passing through.

A new technology for solving this problem uses an overhead camera for optical tracking and tagging of individuals as they pass, issuing an alert if it detects more than one person per authorized entry.