How Much Do You Know About LoRaWAN Security?

LoRaWAN is a remote wide-area network protocol developed by the LoRa Alliance that wirelessly connects "things" to the Internet in regional, national or global networks. The technology meets key Internet of Things (IoT) requirements such as bi-directional communication, end-to-end security, mobility and localized services. Get to know about LoRaWAN module there.

It uses unlicensed spectrum in the ISM band to define the network's communication protocols and system architecture, while the LoRa physical layer establishes remote communication links between remote sensors, beacons and gateways connected to the network. The protocol facilitates the rapid establishment of public or private IoT networks using hardware and software from any location.

How is the Encryption in the Use of LoRaWAN? 

LoRaWAN has a security layer for the network and a security layer for the applications. The application layer security ensures that the network operator does not have access to the end user's application data, while the network security ensures that every node in the network is legitimate. Therefore, the LoRaWAN standard provides two encryption layers.

1. End devices and network servers exchange a 128-bit network session key.

2. At the application level, a unique 128-bit application session key (AppSKey) is shared end-to-end.

The data is encrypted by the node, then re-encrypted via the LoRaWAN protocol and transmitted to the LoRa gateway. The gateway transmits the data to the web server over a standard IP network. The network server decrypts the LoRaWAN data using a network session key (NwkSkey). It then sends the data to the application server, which uses the application session key to decrypt the data (AppSKey).

The encryption is then added to the LoRaWAN communication protocol. However, LoRa transmissions are basic radio wave communications and cannot encrypt themselves. If a LoRaWAN device is connected to the network via wireless activation or OTAA, a 128-bit AppKey is exchanged between the device and the network. The AppKey is used to construct a Message Integrity Code (MIC) when the device sends a join request, and then the server compares the MIC with the AppKey.

If the check is successful, the server generates two new 128-bit keys: the application session key (AppSkey) and the network session key (NetSkey) (NwkSkey). The AppKey is used as the encryption key to send these keys back to the device. The device decrypts and installs the two session keys after receiving the keys.