The ‘Town Crier’ Approach to Monitoring

Abstract

An unconventional approach to tamper and intrusion detection is presented that has significant advantages for transport security, as well as for other aspects of domestic and international nuclear safeguards. The technique is called the ‘town crier’ method. It avoids many of the problems associated with traditional approaches to tamper and intrusion detection. The town crier method involves continuous, real-time monitoring using simple hardware and an anti-alarm strategy. When operated in intrusion detection mode, it utilises unidirectional, extremely low-bandwidth communication encrypted via a rigorously unbreakable cipher (the one-time keypad). In tamper-detection mode, the town crier method relies on anti-evidence to avoid many of the vulnerabilities of conventional tamper-indicating devices. A rudimentary town crier prototype system was constructed, and briefly tested for monitoring cargo inside a truck. Preliminary results are encouraging.