IoT Gateway Development — Best Practices for a Highly Secure Solution
IoT gateways are crucial components of an IoT solution, as they enable connectivity between the IoT sensor network and the cloud. Since they are located between the external internet and the local intranet, they form a very important junction of connectivity.
The IoT gateway has superior software that endows it with higher processing power. It is found that IoT gateways are highly vulnerable to security attacks. Hence, it is important for the gateway to be protected from security threats.
What are the most crucial steps in enabling IoT gateway security?
Integration of IoT gateway security features is essential at the time of design itself. Some of the important aspects to bear in mind at the design phase are as follows:
Secure booting
Securing the booting process is the most basic form of protection for the IoT gateway, throughout its lifespan. It is important to ensure that the booting of the gateway is triggered only by trustworthy and authenticated software. This protects the system against Man in the Middle and Malware attacks.
In order to facilitate a secure boot, the following evaluations are necessary:
a) Check the source of the boot — When the IoT gateway is booted, the source of the command is evaluated and verified using unique Secure Boot keys.
b) Check the content of the boot — To ensure that the IoT gateway device is updated with the correct version of software, the content of the boot should be checked.
Data security
IoT gateway design engineers should touch upon the following points to ensure data security:
a) Security of data exchanged between sensor network and IoT gateway
The data that is transmitted from the sensors to the gateway are usually encrypted. Sensor communication protocols such as WiFi, Z-Wave, ZigBee, 6LoWPAN and LoRaWan have robust built-in security features to enable secure data exchange.
b) Security of data exchanged with cloud
The data transmitted from the IoT gateway device to the cloud servers is encrypted. Security is ensured through security certifications such as TLS or SSL. Usually, the IoT gateway devices are registered with the cloud server and are assigned unique MAC ids. On receiving a connection request from a device, the cloud server performs an authentication of the device’s MAC id. It also validates the security certifications of the IoT gateway device.
Hardware security
Hardware security of the IoT gateway device is ensured through TPM (Trusted Platform Module). The TPM offers additional security to the device, over and above data security and secure booting. Cryptographic keys are used by TPM to protect against data phishing attacks.
Physical security is a crucial aspect as well. The IoT gateway should be designed in such a way that it is resistant to tampering by unauthorized personnel.
a) Chips that manage important functionalities can be configured such that they get destroyed during the process of unauthorized removal.
b) The device casing can also be configured in a way that the device is permanently disabled when the case is opened by unauthorized people.
Bluetooth PAN level security
Bluetooth PAN level security includes various components:
a) Access control modules that provide role-based access to the device for each user
b) Blacklisting or whitelisting of Bluetooth MAC addresses
c) Authentication of FOTA updates
d) Reinforcing security through the use of logging and usage meters which collect information on connections, errors, and other similar lifecycle events
e) Control BLE pairing and bonding
WAN level security
WAN level security can be reinforced in the following ways:
a) Firewalls can be deployed in the network to protect the system against security violations such as network threats, abuse of service or device threats.
b) Disabling the open external ports can protect the IoT gateway device from attacks.
c) SDP interface can form an invisible screen that protects the IoT gateway device against security violations.
d) Access control lists can provide role-based access for individual users.
e) Blacklist or whitelist Bluetooth MAC addresses.
To learn more about IoT security, check out our three part series on this topic.
