Before we get too far, its important to explain exactly what IOT security means:
In its simplest form, IOT security is broken down into zones and trust boundaries. Typically the zones are defined as follows:
- Devices – IOT devices that capture and send data
- Field Gateway – Devices that can aggregate data to and from devices
- Cloud Gateways – Endpoint that receives / sends data and commands to Field Gateways or directly do devices
- Services – The services that “do work” on the data that is received from the IOT devices (via the gateways)
Trust boundaries are where data moves between zones. During this movement across boundaries the data can be subject to Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of privilege commonly called STRIDE. For more information about STRIDE, visit this link). Its important to make sure that your IOT devices and data are secure across all zones and trust boundaries.
IOT Security in AzureThe best way to make sure that your application is secure is by leveraging threat modeling during the design / implementation phase. This forces the design of the application to take security into consideration instead of adding it on at the very end. Just like all of its other products, Microsoft leveraged threat modeling for the Azure IOT components.
I want to go through how Azure handles security across the various trust boundaries.
Device to Field GatewayIOT Devices and Field gateways are very similar and usually connect in much the same way. Typically the security risks from a device to Field gateway perspective are physical / hardware related. This means its important to keep your IOT devices secure physically from harm and intrusions. While harm can be done while transmitting data to / from them, typically its more physical than digital.
Device / Field Gateway to Cloud GatewayIn Azure IOT, the Cloud gateway is called the IOT Hub. The IOT hub uses time sensitive security tokens to authenticate devices and services to avoid sending keys over the wire. Although this sounds complex, the Azure IOT SK’s provide simple and easy ways of automatically generating tokens. Here is a great walkthrough on how that’s done.
Inside the hub itself you can set up Shared Access policies that allow devices that connect certain abilities inside of azure. if configured correctly, this greatly reduces risk to data tampering since devices do not have have direct access to data stores, etc..
This is by far the easiest thing to secure in an IOT implementation. Azure
IOT suite allows users to easily configure connections between the IOT hub and
other components like Stream Analytics, Azure Data Lake, SQL Azure, etc. All of
these components are only available in your own Azure subscription and should
reside inside the same data center to prevent data from potentially being
tampered with while in transit (although that’s incredibly unlikely since they
are all Microsoft data centers). Since only you can access and configure the
components and the data is processed and analyzed in the same data center,
security risk is very low.
Cloud Gateway to Services
The important thing to remember about security in the Services zone is that if you have any VPN’s to Azure, then that data is potentially venerable there and the normal VPN security should be taken in order to make sure that no one inside of your network can access the data.
As you can see, IOT security is important, but it can be easy if you understand the threats it poses and know how to mitigate them. Leveraging Azure IOT suite makes an IOT implementation quick and easy. Please contact Flex Manage to learn more about IoT and how we can ensure your devices and data stay secure.