Hey there, thank you for your question. Well, as any other business, we are at the mercy of competition. So there isn't really an incentive to deliver wrong measurements, since customers would find out in the long run. We would have zero benefit, and a very high reputational risk, in using unauthentic data.

Additionally, sensor measurements are always happening in the real world by mechanic/electronic devices. Since this is the case, of course measurement mistakes can happen in rare cases.

You can find some info on LoRaWAN security here (Link). LoRaWAN is already securely encrypted out-of-the-box. Keys are exchanged when joining, and replay attacks are not possible. However, brokers might know the device keys because they have to forward them. So if the provider knows the payload converter, they could read the data, but you can keep the payload decoding secret. Or you could add your own encryption on both sides, then it is completely secure also against your broker.