Effective Anti-Tailgating Technologies

Tailgating – the practice of an unauthorized individual gaining building or area access by following behind an authorized individual – is a decades-old security problem.

Q:      We’ve been told by senior management that we MUST eliminate tailgating immediately. A high-multi-million-dollar project is on hold because our tailgating poses an unacceptable confidential information risk to a partner company’s data.

A:      Until now, eliminating tailgating has always been a tough challenge, without a high degree of real-time assurance. New smart technology is providing help.

This year, at ISC West 2018, I learned of two affordable anti-tailgating products that are making significant inroads in providing real-time anti-tailgating control while supporting high-volume traffic, through the incorporation of advanced technology whose machine-learning capabilities derive from the high-dollar research that has been pouring into autonomous driving and aviation technology.  

New Anti-Tailgating Technology

Both products model the pedestrian scene in front of the secure area entrance point (turnstiles in one case and single doors the other). Each product’s entrance/door scene analysis is based on a different type of smart sensor, although the two sensors have some elements in common. Each sensor uses eye-safe near-infrared light, one by near-infrared light emitter, and the other by near-infrared laser. Both technologies use the same Time-Of-Flight (TOF) measurement technique. TOF is a method of determining distance based on the known speed of light, measuring the time-of-flight (travel time) of a light signal sent between a light emitter and reflected back to the light receiver sensors from object surfaces in a target area.

Both products are examples of an emerging category of 21st-century security products that apply smart sensors and advanced real-time analytics to gain much higher levels of product performance and security-effectiveness than has been possible with 20th-century technology. Both products can distinguish between a single person with a backpack, luggage or a stroller and two people close together or touching. They can track multiple people in the entry zone, which can be as many as 7 or 9 people, depending upon the size of the area. Both products require access control system integration, which can be accomplished via traditional general-purpose input/output connections (GPIO) or via an SDK for a richer integration that includes additional data for the access control system.

In the past, security turnstiles have been limited to narrow lanes that constrict the flow of people to one person at a time, so that controlled access can be achieved by blocking the passage of unauthorized individuals. The trouble with that approach is that the majority of individuals are authorized, with unauthorized passage attempts being the exception. It doesn’t make sense to slow down all traffic by using narrow single-person lanes just for the exception cases that infrequently occur. Additionally, the wider lanes and entryways limit the impact of the slow or stop-and-go behavior of an unauthorized person and easily accommodate individuals with rolling cases, luggage, boxes, and other business-normal variations to the usual single-person traffic.

High-Volume Optical Turnstile Control

Digicon’s dViator product is a brilliant innovation to their dFlow turnstile/pedestrian gate control line. It can provide wide turnstile aisles that multiple authorized people can traverse through at high speed, and in opposite directions, and when unauthorized people enter the turnstile, they are prevented from entering the access-controlled area and are instead guided to a security inspection point or back in front of the turnstile.

See a video of Digicon’s dViator product in action here: http://bit.ly/dViator. This video shows the wide lane option which is ADA compatible. Lane widths are customizable, but Digicon suggests as a default that all dFlow and dViator lanes be ADA compatible. You will notice in the video how the speed of the turnstile’s control barriers is slow or fast, based upon the speed of travel of the offender, which is made possible by the high-speed processing of the sensor algorithms. You’ll also notice how authorized users go quickly into the secure area because that is the default open-channel configuration of the turnstile. When unauthorized users arrive, you can see how the exit end of the turnstile lane reconfigures to shift one or more offenders into a screening area or back to the entrance area.

To do this, dViator uses its overhead sensor to create and maintain a real-time 3D map of the turnstile area, tracking each individual within the turnstile and visually displaying their location position on a LED-powered colored light band display that provides a separate color band for each individual group in the turnstile. The light bands can be configured, for example, to use one color for a university’s employees and teaching staff and another color for students. Unauthorized individuals get a red band so that the moment they enter the turnstile, they can know they are identified as unauthorized and are being tracked.

The locator band follows pedestrian motion exactly, whether they move forward, back or stop. If they stop in a wide turnstile lane, other individuals can move past them and the overall flow through the lane continues. A display monitor can inform unauthorized users of the reason for their denial of access and instruct them where they should go next – all of which occurs outside the turnstile lane, while the ordinary flow of people continues.

The dViator time-of-flight sensor cannot be fooled by techniques that trick traditional light-sensor-based optical turnstiles, because the dViator’s analytics recognize each individual in 3D and never lose track of them despite such attempts.

Single-Door Anti-Tailgating Control

Orion Entrance Control’s DoorGuard product is a small (fits in the palm of your hand), self-contained solid-state anti-tailgating device for mounting in, on or below the ceiling, over the entry area to a door. DoorGuard uses Quanergy’s S3-Qi solid state LIDAR-based sensor technology. LIDAR is a name that was originally a blend of the words “light” and “radar”, but now is said to stand for “Light Detection and Ranging” or “Laser Imaging, Detection and Ranging” – depending on whom you ask. DoorGuard’s machine-learning algorithms are designed for security doors including ADA doors, and work with swinging doors, sliding doors, and virtual or no-door entry points.

Based on the Quanergy sensor’s data, DoorGuard works by locating and tracking individuals in the configurable entry zone in front of the door. Individuals presenting a credential located at or near the controlled door are granted access. Individuals who do not have a valid credential or do not present one are denied access, or if the door is held open for them, DoorGuard alarms. When no valid credential is presented at virtual or no-door entry points, DoorGuard signals the access control system that an unauthorized entry has occurred. DoorGuard supports high traffic levels through its “card-stacking” feature, which allows up to 50 people to present their card at the door and pass through, without requiring the door to close. DoorGuard will alarm if an unauthorized entry occurs in a card-stacking situation. DoorGuard can be set to detect crowding at the entrance, which activates when people who have not presented a valid card are too close to the door. When crowding detection is active, access can be denied even to authorized users, if desired, to minimize the risk of tailgating.

DoorGuard costs about 30 percent less than current door anti-tailgating solutions.

Manufacturer Consultation

Due to the wide range of performance and capabilities of these products, it is a good idea to get a full understanding of exactly how they work, and to consult the manufacturer about the specifics of your application, as there are entrance/door and pedestrian traffic dynamics to consider and options that also require consideration.