Bluetooth

1. What is Bluetooth in Browser Fingerprinting

The Web Bluetooth API, available in Chromium-based browsers, allows websites to interact with nearby Bluetooth Low Energy (BLE) devices. While intended for apps like fitness trackers, smart devices, and IoT integrations, it has become a fingerprinting signal that tracks:

Whether the API is available or enabled
Whether a Bluetooth adapter exists and is active
The availability status of navigator.bluetooth

Even without scanning or connecting to actual devices, the presence and behavior of this API can help platforms distinguish:

Between real and spoofed browser sessions
Whether automation or anti-fingerprint tools are present

This data contributes to complex browser canvassing systems, such as browser uniqueness scores and session trust scoring, designed to detect fraud and multi-account usage.

2. Common Data Collected by Sites (FlashID Protection Scope)

Most browser fingerprinting systems analyze at least two key points related to Bluetooth fingerprinting:

Data Point	How It’s Used
API Status	Tracks whether the `navigator.bluetooth` API is Enabled or missing. Anonymization tools may disable the API, making the browser stand out.
Bluetooth Adapter	Detects the presence of a Bluetooth adapter by checking for available devices or status changes. Can signal device uniqueness or spoofing behavior.

Additional combinations of detection include:

Mock scanning or passive BLE signal inference attempts
Permission behavior simulation: Some platforms test how a browser handles Bluetooth request prompts
Correlating Bluetooth state with system information anomalies (e.g., battery, motion sensors, or audio devices)

3. How FlashID Generates and Protects Bluetooth Fingerprints

FlashID ensures full control and spoofing ability over navigator.bluetooth, protecting user profiles from unwanted signatures or behavioral linkage.

Bluetooth API Control

API Availability Toggle: FlashID lets users control whether the navigator.bluetooth API is present, missing, or mimics real user agent behavior
Permissions Masking: Simulate user denial, prompt delay, or temporary access inconsistency to reflect organic browsing patterns

Bluetooth Adapter Spoofing

Adapter Existence Masking: FlashID can report a managed state for the adapter — such as true, false, or simulatevariable conditions based on the device profile
Device Emulation: Responses from .requestDevice() are spoofed or suppressed based on a fake environment behavior pattern
Error & Timing Injection: Introduce randomized delays or errors (NotFoundError, SecurityError) to make API behavior indistinguishable from native browsers

This mode ensures even environments with simulated device norms — like single profile reuse across different locations or contents — do not leak Bluetooth identifiers, and avoid triggering detection systems that use BLE as one of their fingerprint vectors.