Chapter 12. Monitoring and Metering

The market is not an invention of capitalism. It has existed for centuries. It is an invention of civilization.

— Mikhail Gorbachev


Many secure systems are concerned with monitoring and metering the environment. They go back a long way. James Watt, the inventor of the steam engine, licensed his patents using a sealed counter that measured the number of revolutions an engine had made; his inspectors read these from time to time and billed the licensee for royalties.

Electronic systems that use cryptography and tamper-resistance are rapidly displacing older mechanical systems, and also opening up all sorts of new applications. Ticketing is a huge application, from transport tickets through sports tickets to theatre tickets; my case study for ticketing is the meters used for utilities such as gas and electricity. Then I'll turn to vehicle systems; the most familiar of these may be taxi meters but I'll mainly discuss tachographs — devices used in Europe to record the speed and working hours of truck and coach drivers, and in the USA to record the comings and goings of bank trucks. My third case study is the electronic postage meter used to frank letters.

You will recall that in order to defeat a burglar alarm it is sufficient to make it appear unreliable. Such service-denial attacks can be tricky enough to deal with; meters add further subtleties.

When we discussed an alarm in a bank vault, we were largely concerned with attacks on communications ...

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