Internet of Things (IoT) refers to the process of connecting cyber-physical objects to the Internet, enabling the exchange of data over wireless communication networks with limited human intervention. These communication networks use licensed spectrum or unlicensed spectrum. Instead of licenced spectrum used by Narrowband Internet of things (NB-IoT) and Long-Term Evolution for Machines (LTE-M), SigFox, MIoTy, and Long Range Wireless Area Network (LoRaWAN) employ unlicenced spectrum for communication between the network entities. Among wireless networks using unlicensed spectrum, LoRaWAN is the most used network in many applications (smart farming, smart building, smart metering) but its presents several vulnerabilities. This paper studies the LoRaWAN threats, malicious attacks and mitigation against attacks.
Internet of Things (IoT) is an essential element that has
revolutionized the Information and Communication
Technology sector (ICT). Over the past decade, it has been the
focus of much academic and industrial interest, with the
purpose of making buildings, cities, agriculture and
environment smart. This technology refers to the process of
connecting cyberphysical objects (machines) to the
Internet, enabling the exchange (sending and receiving) of data
over wireless communication networks with limited human
intervention. These machines are embedded devices which
present characteristics such as a low energy consumption,
a low computing power, a small size, a small price and a
capacity to communicate within a wireless network. There
are many wireless communication networks classified in
terms of energy consumption and communication range. In
terms of energy consumption, they can be divided into low
power communication (NFC – Near Field Communication,
RFID – Radio Frequency Identifier, Z-Wave, Zigbee, BLE
– Bluetooth Low Energy, LTE-M – Long Term
EvolutionMachine, NB-IoT – Narrowband IoT, SigFox and LoRaWAN)
and high-power communication technologies (Bluetooth,
Wi-Fi – Wireless Fidelity, 3G, 4G and 5G). Regarding the
communication coverage, there are short range
communication networks (< 1km) (e.g. NFC, RFID, Wi-Fi, Bluetooth,
BLE, Z-Wave and Zigbee) and long-range communication
networks (1-15 km) (3G, 4G, 5G, LTE-M, NB-IoT, Sigfox, and
LoRaWAN) [
LoRaWAN is a low cost, low power and long-range
communication network that is developed to fill a gap in IoT
communications. Using this technology belonging to Low
Power Wide Area Networks (LPWAN), sensors or actuators
can send signals over 5 km in urban areas and up to 15 km
in sub-urban areas. Instead of licenced spectrum used by
LoRaWAN’s main competitors (a.k.a other LPWANs) like
NB-IoT and LTE-M, LoRaWAN employs unlicenced
spectrum for communication between the network entities [
These advantages allow LoRaWAN to be considered as the
technology that is improving the operations of many
industrial sectors (e.g. agriculture, environment) as a
largescale remote monitoring is then possible. However, like
any computer network, and particularly wireless network,
this technology sufers from many security problems that
can be defined following the three security criteria:
availability, integrity and confidentiality. Many specifications of
LoRaWAN have been published since its development by
Semtech Corporation [
This paper reviews LoRaWAN attacks, vulnerabilities and security measures. It provides a short review and an analysis of LoRaWAN robustness and gives perspectives about the robustness improvement. The outline of the paper is presented as follows: the theoretical background is described (§II), the literature review is presented (§III), the paper is ifnalized by the conclusion (§IV).
Before explaining the behaviour of LoRaWAN protocol, let us compare LoRaWAN to the LoRa (Long Range) modulation. LoRa is the modulation type used between two LoRa devices or between a LoRa device and a gateway (cf Fig. 1). The LoRaWAN term is employed when end-devices can communicate with the LoRaWAN servers. LoRaWAN is the extended version of LoRa technology which connects enddevices to the network server. It includes LoRa modulation that operates at the physical layer of the network. Fig. 1 shows the LoRaWAN topology.
LoRaWAN network includes three sub networks. There is the LoRa radio frequency network presenting a star topology, the backhaul network connecting Gateways and Network Servers using Mesh topology or partial Mesh topology and the backhaul network connecting Network Servers with Join and Application Servers. Beside the two servers (Network Server and Application Server) used in LoRaWAN v1.0, a new server called Join Server is added in LoRaWAN v1.1 to manage the OTAA (Over the Air Activation) procedure more securely. The Join Server has been added in the network to orchestrate in a more secure way the joinCEUR
ceur-ws.org ing procedure used by end-devices (LoRa devices) to join the network. Also, LoRaWAN v1.1 integrated roaming and mobility techniques for the end-devices by employing extra servers called Join Server (JS), forwarding Network Server (fNS), serving Network Server (sNS).
The joining procedure creates mutual authentication
between an end-device and the LoRaWAN network to which
it is linked. Two joining procedures are used to connect
the end-devices to the servers. There are Activation By
Personalization (ABP) and Over-The-Air Activation (OTAA).
Among them, OTAA procedure is the more secure. It
provides a more flexible and secure way to establish session
keys with the network servers. In OTAA, authentication
is required for devices using two diferent keys for each
device that are generated each time the device joins the
network: Network session Key (NwkSKey) and the
Application session Key (AppSKey). Using two diferent keys
makes it is more dificult to tamper with or read application
data, even if one of the keys has been compromised. These
keys are generated during the two root keys (NwkKey and
AppKey) design. The ABP procedure is not so secure as the
end-devices are directly connected to the network without
join request and join-accept procedures [
LoRaWAN security challenges are related to diferent parts of the network. The main parts are the network entities (gateways, servers, and end-devices), the key distribution methods, the network implementation, and the roaming techniques integrated in LoRaWAN v1.1, and the backward compatibility challenges. In this section, LoRaWAN vulnerabilities and attacks are presented.
Network security vulnerabilities are weaknesses within the system’s software, hardware, or organizational processes. Their can be either non-physical or physical. The main vulnerabilities of LoRaWAN are: the long times communication induced by Long Range transmission, the coexistence problem of LoRa, and backward compatibility challenges. • Long times communication induced by Long Range transmission Spreading Factor (SF) is a parameter used in spread spectrum modulation techniques like Long Range (LoRa) modulation, to control the spreading of a signal over a wider bandwidth. The larger SF is, the longer the distance the device can receive or transmit. Eight Spreading Factor (SF5, SF6, SF7, SF8, SF9, SF10, SF11 and SF12) are used in LoRa transmissions whereas in LoRaWAN six SF are used (SF7 to SF12). The elapsed time on air of a LoRaWAN messages increases with the Spreading Factor (SF) and then the transmission distance. Indeed, the time on air increases with the symbol transmission time ( ) (1). The symbol transmission time is defined by the formula (2). For a fixed bandwidth, the symbol transmission time increases with the spreading factor value (cf Fig. 3). In particular, symbol duration increases by a factor of 2 from one SF to the next. As shown on this figure, the start frequency (low frequency) is the channel frequency (center frequency) minus the channel bandwidth divided by two. The ifnal frequency (high frequency) is the channel frequency plus the channel bandwidth divided by two. − − = = ℎ 2 × (1) (2) As high SF (up to SF12) is required for the network edge end-devices to communicate with the gateway, a mock device can intercept messages or falsify packets intended for the gateway. Furthermore, there is no time-related information in LoRaWAN packet. As LoRaWAN packet structure does not include any time-based signature or data to validate the time of
the message, this vulnerability is used to employ a wormhole attack. • Coexistence problem of LoRa
LoRa transmission is sensible to interference issues
such as interference from Cellular Networks (Global
System for Mobile Communications (GSM),
Universal Mobile Telecommunications System (UMTS), and
Long Term Evolution (LTE)) (which can make less
sensitive LoRa receivers, making it hard to receive
weak signals) and In-Band and Out-of-Band
interference [
Backward compatibility problems occur when a newer version of a software or hardware system is not able to work with the data or functionality of an older version. In LoRaWAN security case, LoRaWAN v1.1 aims to improve security, but it may be dificult to ensure backward compatibility with devices using earlier versions (v1.0). In fact, the Network Server is responsible for deciding which protocol version to exploit and chooses the highest common version between itself and the End-Device (ED). As LoRaWAN v1.0 presents more security weaknesses than LoRaWAN v1.1, the backward compatibility ofered by the evolved version could constitute a vulnerability. • Jamming attack
Radio Jamming attack consists in disrupting the LoRa radio transmission by transmitting a powerful radio signal in the proximity of application devices. It is possible to jam LoRa messages using well timed malicious transmissions. This attack is usually performed using a dedicated hardware (ie Commercialof-the-shelf (COTS)) to jam LoRa devices. There are no real countermeasures to prevent this attack. But network administrators can easily detect jamming when devices transmitting into the network start to disappear. They may then decide to switch to another frequency in the band to avoid the impact of jamming. • Selective jamming attack
Selective jamming constitutes the most sophisticated
and eficient jamming technique which could be
effective using a COTS hardware by extending the
jammer with additional software to target a specific
device address [
Replay attack is performed on security protocol by repeating the available data transmitted by malicious entity Fig. 4). Replay attack is an attack on the security protocol that consists in resending captured messages from the end-devices. Its objective is in the Denial of Service of an end-device This attack is possible using the communication frequencies and channels to snif data from transmission between devices (end-devices and Gateways). Predator may intercept and replay legitimate messages, compromising the network’s security. The use of frame counters process helps LoRaWAN network to know if the message is sent by the gateway instead of a malicious device. Indeed, once the end-device is activated, both frame counters (from the end-device and the gateway) are set to 0, and each message coming from the gateway, or the device increments the counters. By this way, if a message is received with a lower frame counter than the last message, it is ignored. But this process could be exploited by attackers to produce a Denial of Service. • Wormhole attacks
A wormhole attack is an attack which can be
performed against a LoRaWAN network. This attack
consists in packet snifing and replaying them. One
malicious device captures the packets from one
device and transmits them to another distant located
device to replay the captured packet. The two
devices which participate to this attack are the snifer
and the jammer. The snifer captures packets and,
transmits signal to the jammer informing that it
apprehended the packet [
As already presented, LoRaWAN implements
channel confidentiality through AES in counter mode,
where the block counter value is exploited as an
input. During a counter reset, the key will remain in
place, meaning that the block cipher will
reconstitute the same key material. An attacker can exploit
this comportment to decrypt messages.
• Bit-Flipping Attack (Man-in-the-Middle, MitM)
LoRaWAN messages are encrypted and carry a MIC.
But the encryption and the integrity check are
managed at diferent locations inside a message frame.
The payload encryption is handled by the
Application Server, while the MIC is checked and terminated
by the infrastructure provider (Network Server (NS))
[
LoRaWAN gateways are obeying relays and then constitute the weakest link of the network. Any kind of security problem on this node would interrupt communication between the end-devices and the servers. One of the attacks faced by LoRaWAN gateways is the use of a rogue gateway that acts like as a legitimate gateway. One can distinguish two kind of attacks: LoRa class B attack (beacon synchronization Denial of Service (DoS) attack) and Impersonation attack.
– Beacon synchronization DoS attack
This attack is a typical malicious gateway attack that use class B device vulnerability. In LoRaWAN, class B beacons received in downlink transmission are not secured by any methods, indicating that an attacker can deploy a malicious gateway to send counterfeit beacons. The result is that class B enddevices will receive messages in windows outof-sync with the malicious gateway. By sending out beacons randomly a malicious gateway could desynchronize an end device from receiving windows of another gateway. This could cause a denial of service, as the legitimate gateway sends messages when the end device is not receiving. To deal with this attack, a key should be exploited by gateways to authenticate beacons communications. – Impersonation attack
Gateways can also be impersonated to create attacks against end-devices. End-devices can be listened to and their network address can be determined. Furthermore, a triangulation method (minimum 3 gateways are required in this case to perform the intended capturing attack the end-device).
Besides the attacks previously presented, there are also network spoofing attack, selective forwarding attack, sinkhole or blackhole attack ... In the following section, a short literature review of papers about LoRaWAN security is presented.
Table 2 presents a literature review on papers related to LoRaWAN security.
Reactive jamming using Channel Activity Detection (CAD) mechanism detection, using a combination of channel hopping and transmission, and using CAD detection, channel hopping and transmission
This paper presents a security analysis of LoRaWAN v1.1. The main vulnerabilities and attacks are summarized. It gives a review on papers that address this network security. It is shown that the main physical layer security attacks are jamming and attack replay while other attacks can afect the network availability, integrity and confidentiality.
This work has been carried out under support from the ARES within the frame of a post-doctoral mobility grant in the Electromagnetism and Telecommunications Service (UMONS/FPMs/Belgium).