Prometheus Security Group Global has been granted a U.S. patent for a novel method of securing legacy analog circuits in physical security systems, industrial control systems (SCADA), and premise access control applications.

The patent (U.S. Publication No. 20220021545), titled “Novel Method of Securing Legacy Analog Sensor Circuits Used in Physical Security, Premise Access Control and Industrial SCADA Applications,” introduces a unique approach to encrypt and authenticate analog sensors and facility controls transforming data at the edge — without the need for complete system replacement.

The patent covers the design and implementation of a Universal Field Panel (UFP) powered by a secure microcontroller that authenticates and encrypts both sensor inputs and control outputs. Leveraging a Digital Encrypted Security Interface (DESI), the system modernizes analog infrastructure with authenticated digital cryptography, enabling secure communication between legacy devices and command systems.

“Most legacy intrusion detection and physical access control systems still rely on electronic techniques from the 1940s. This technology brings those systems into the modern age — featuring strong encryption, edge authentication, and seamless integration with today’s commercial platforms, while reusing the existing wiring plant,” said Jeremy Freeze-Skret, inventor and chief architect, Prometheus Security Group.

Key Innovations Include:

• Drop-in compatibility with existing analog sensor infrastructure (e.g., motion detectors, door contacts, relay outputs)
• Edge authentication and encryption using scalable public key infrastructure PKI cryptography
• Tamper detection, latching mechanisms, and watchdog timers to mitigate spoofing and replay attacks
• Failover-ready architecture with support for controlling redundancy and public-key lifecycle management

Unlike traditional physical security panels, the UFP with the DESI enables encrypted communication from sensor to server, eliminating blind spots and authentication gaps in security environments ranging from critical infrastructure and military bases to data centers and commercial applications.