What is MAC Randomization?
A MAC address is a unique identifier assigned to a device’s network interface. MAC addresses generally remain constant and allow networks to recognize a device. With MAC randomization, the device periodically changes this identifier, making it more difficult to track activity across connections.
You may have heard of MAC Randomization recently due to the upcoming iOS 18 MAC randomization features. Traditionally, MAC addresses remained constant, but with MAC address rotation iOS 18 and macOS 15 are introducing, devices will periodically change this identifier, making it more challenging to track activity across different network connections.
How Does MAC Address Randomization Work?
MAC address randomization generates a new MAC address each time a device connects to a WiFi network. Some devices randomize MAC addresses each time they connect to a new network while others change periodically.
With the iOS 18 and macOS 15 network security updates, Apple is implementing rotations, and devices will rotate their MAC address approximately every two weeks. This change applies particularly to iOS 18 and macOS 15 weak security networks and public Wi-Fi. The rotation may occur sooner if a user manually “forgets” a network.
Why is MAC Randomization Important?
MAC randomization can improve user privacy by limiting device tracking across different networks. With MAC address randomization, users can reduce profiling to improve online anonymity. However, this also means that those who would like to seamlessly connect to public WiFi networks may no longer be able to do so.
What are the Pros and Cons of Using a Randomized MAC Address?
The main benefit of MAC randomization is increased user privacy. This can benefit consumers who don’t want to be tracked. However, an unintended side effect is that it could reduce customer experience in getting onto the WiFi when they are used to a seamless connection.
Pros:
- User Privacy: MAC randomization reduces the ability of third parties to track a device’s network activities across different locations.
- Protection in Public Networks: Randomization protects against unsolicited tracking in public WiFi networks.
Cons:
- Impact on Network Management: MAC randomization can disrupt visitor behavior analytics and affect metrics like return rate and visit duration.
- Reduced Targeting: Advertisers relying on data from MAC address profiles will be limited in personalized targeting and messaging.
- Potential Connectivity Issues: Some devices might experience connectivity issues with some networks that require consistent MAC addresses for authentication or network services.
How Does MAC Randomization Affect Secure Connections?
MAC randomization does not interfere with common protocols protecting secure connection data (ex., HTTPS), and encrypting data between a device and a server remains mostly unaffected. However, some network security measures that rely on consistent MAC addresses (ex., whitelisting) could see disruptions and lead to connection issues or additional authentication steps each time the device connects.
Does MAC Randomization Improve Security?
MAC randomization generally improves privacy rather than security. MAC randomization does not directly protect against network attacks, malware, or other security threats.
Can Randomized MAC Addresses Be Tracked?
Although MAC randomization increases privacy, it is still possible for some tracking techniques to identify and track devices.
- Correlation Tracking: If a device connects to the same networks frequently, randomized MAC addresses and behavior can be correlated.
- Passive Fingerprinting: Devices broadcast other identifiers like signal strength, device type, or network behavior. These identifiers can help identify and track a device even when its MAC address is randomized.
MAC address randomization is not entirely immune to all tracking methods.
How is Apple iOS 18 and MacOS 15 Changing MAC Address Behavior?
Apple will begin rotating a device’s MAC address every two weeks and potentially sooner if users manually “forgets” a network.
How Will iOS 18 MAC Address Rotation Impact Businesses?
The introduction of more frequent MAC address rotation in iOS 18 presents several challenges:
Reduced Reliability of MAC-based Analytics: Customer insights and loyalty programs may become less accurate.
Network Access Control Complications: Whitelisting and security filtering processes may need revision.Guest Service Disruptions: Potential issues with seamless access for returning visitors, especially on public Wi-Fi, as well as a reduction in users authenticating onto your public WiFi network
Preparing for iOS MAC Address Rotation
The evolution of MAC randomization, particularly with the upcoming changes in iOS 18, marks a significant shift in network privacy and security. While it presents challenges for businesses and network administrators, it also offers opportunities to enhance security practices and improve user privacy, especially on public and weak security networks.
To help your business prepare for these upcoming changes, we recently ran webinar where we discussed ways to mitigate the effects of the changes: iOS18 Will break Public WiFi Networks.
You can view the recording and download other useful resources here.