Zero Trust, all the way to the sensor.

Embedded Zero Trust is built into the device, not bolted onto the network around it. Each PSG controller and interface carries its own cryptographic identity and performs its own authentication and encryption at the point of detection. There is no gateway vouching for the sensor. The sensor speaks for itself, and it can prove who it is.

On a legacy supervised loop, the DESI Controller replaces the end-of-line resistor. The wire, conduit, sensor and door hardware stay where they are. From that point the loop carries authenticated, encrypted signaling over the same pair, and the panel accepts a change of state only when the device on the other end proves it sent it. Modernization without rip-and-replace.

Cameras, readers, sensors, fence detection, wiring and conduit stay. Command and control, video management and building platforms stay. What changes is the trust model: devices are verified before they join the system, every event is authenticated before anyone acts on it, and stored data keeps its chain of custody. That is the Four Pillars of Trust, from the far edge to the enterprise.

Physical security systems were built to detect physical events, not to defend against cyber manipulation. As they converge with IT, OT, cloud and AI, every field device is part of the attack surface, and automation acts on whatever those devices report. A manipulated signal means a false alarm, a missed intrusion, or a decision made on bad data. Trust not established at the source cannot be assumed anywhere else.