Cold chain telemetry you can prove nobody altered

A temperature record is evidence. If it can be edited after the fact without
leaving a trace, it is evidence of nothing.

The chain has four links, and each one needs to be able to say what it
received and what it passed on: the sensor, the gateway, the historian, and the
report an auditor eventually reads.

The question is not "do we have the data?" It is "can we show that this is the
data we recorded at the time?"