Prevalence of Mobile Fingerprinting SDK

Biometrics is a powerful tool that can significantly improve the security of in-app experiences. It provides a strong and reliable method for authentication, which is more secure than traditional methods such as verification codes or security questions, and it is also faster and more convenient for the user. For example, fingerprint recognition is already used on Apple iPhones and Samsung smartphones to unlock devices with a single touch.

Despite these benefits, global IP blacklist and blocklist use of fingerprinting SDK in apps comes at a cost. This technology can be used by third parties to track and target users in violation of their privacy rights. Our research shows that fingerprinting SDKs are prevalent in a wide range of apps, with some sensitive app categories such as medical and finance being more susceptible to cross-app tracking than others.

RQ2: Market Reach

Figure 7 reveals the prevalence of SDKs with fingerprinting behavior across app categories. The color gradients in the chart reflect the proportion of apps containing these types of SDKs in each app category (a). Note that for some categories, such as games or comics, the vast majority of apps containing these SDKs are not the most popular, but rather, those which have the highest number of installs.

The use of SDKs with fingerprinting behavior in a variety of applications is alarming. However, it is reassuring to see that some sensitive app categories appear to have taken a stronger stance on user privacy. For example, when normalized by install volume, only 30% of apps in the medical category include a fingerprinting-like SDK. It is possible that these apps primarily use this functionality for analytics purposes, as opposed to advertising.