" "Sigfox-enabled devices have a built-in behaviour; when this requires data to be transmitted or received, a device will communicate via a radio message. Each message is picked up by several access stations and is delivered to the Sigfox cloud network over a secure VPN, which then relays it to a predefined destination, typically an IoT application. Because Sigfox devices don't have IP addresses, they are not addressable for rogue hackers to gain access.""
This is nonsense on many levels.
1) The Cloud uses IP and I doubt is secure.
2) None of my 433MHz RF devices, 864MHz devices, IR Remotes use IP and are not secure.
3) Native GSM isn't secure and doesn't use IP. they are using out of date broken encryption
4) 3G could be secure, but they don't bother, they are using out of date broken encryption. Internet traffic (IP) is a layer on top.
The voice, 3G video and SMS isn't currently secure. Many embedded devices use non-IP 245Kbps 3G modes or even 14.4K GSM modem modes.
Not using IP doesn't make anything secure. VPNs only protect the link, not endpoints or apps.
Oyster cards and other NFC "wireless devices" don't use IP and are not secure. Contactless payment cards and RFID price tags are not secure (tech designed to replace barcodes in warehouses, so security wasn't in the design, added later).
Barcodes and QR codes are not secure and don't use IP. Such fun to be had printing your own QR stickers for the shops ...