Bluetooth 6.1 Improves User Privacy with Smarter Address Randomization

The Bluetooth Special Interest Group (SIG) has officially announced the release of Bluetooth Core Specification 6.1, marking a major upgrade to the widely used wireless communication technology. The new version comes with significant improvements focused on user privacy and device power efficiency, two key areas of concern in today’s connected world.

Enhanced Privacy with Randomized RPA Updates

One of the most important features introduced in Bluetooth 6.1 is improved device privacy through randomized Resolvable Private Address (RPA) updates.

An RPA is a temporary Bluetooth address that replaces a device’s permanent MAC address to help protect user identity. It is used by devices like smartphones, smartwatches, earbuds, and fitness trackers to communicate securely without exposing their real identity. Trusted devices can still reconnect using RPA, but third parties find it harder to track or trace the user.

Previously, these RPAs were refreshed at regular, fixed intervals — usually every 15 minutes. While this offered a basic level of privacy, it was still predictable. Hackers or trackers could exploit these patterns in what are known as correlation attacks, where they analyze repeated connections over time to identify a device or user.

Bluetooth 6.1 now takes privacy a step further by making RPA updates randomized instead of predictable. The new specification allows these updates to happen at any random time between 8 and 15 minutes (as default). Even better, developers can now set custom timing ranges — from as little as 1 second to as much as 1 hour — depending on their privacy and performance needs.

This randomization is handled by the Bluetooth Controller, which uses a NIST-approved random number generator to select the timing for each RPA update. Because there is no fixed pattern, it becomes significantly more difficult for third-party observers to track or identify Bluetooth devices over time.

According to SIG, “Randomizing the timing of address changes makes it much more difficult for third parties to track or correlate device activity over time.”

This improvement strengthens privacy protection for users in public spaces such as airports, shopping malls, offices, and events — places where Bluetooth trackers can sometimes be misused for surveillance or marketing.

Improved Battery Life and Power Efficiency

In addition to better privacy, Bluetooth 6.1 also brings noticeable gains in power efficiency, especially for smaller battery-powered devices like smartwatches, fitness bands, wireless earphones, and IoT sensors.

In earlier Bluetooth versions, the host device — usually a smartphone or wearable — needed to stay active in order to manage the RPA updates. This meant more CPU usage, memory operations, and ultimately more battery drain.

Now, with Bluetooth 6.1, the Bluetooth Controller (the chip that handles wireless communication) can autonomously manage the entire RPA update process. It no longer needs to “wake up” the main processor every time it refreshes the address.

By reducing unnecessary system activity, devices save power and extend battery life. This is a big win for wearable and IoT manufacturers, where longer battery life is a top priority.

For instance, a fitness tracker that previously needed charging every 4 days might now last an extra day or more, simply due to more efficient RPA handling in Bluetooth 6.1.