AmIUnique Android

This repository contains AmIUnique device fingerprinting application and library source code.

It accompanies the paper:

EXADPrinter: Semi-Exhaustive Permissionless Device Fingerprinting Within the Android Ecosystem (PETS 2026)

Citation

If you use this artifact in your research, please cite:

@article{bouhenniche2026exadprinter,
  author  = {Bouhenniche Sihem, Laperdrix Pierre, Rudametkin Walter },
  title   = {EXADPrinter: Semi-Exhaustive Permissionless Device Fingerprinting Within the Android Ecosystem},
  journal = {Proceedings on Privacy Enhancing Technologies},
  year    = {2026},
  note    = {To appear (PETS 2026)}
}

📱 AmIUnique Android Application

The AmIUnique Android application is a demonstration app that integrates EXADPrinterLib to collect device fingerprints on Android devices. The application extracts a large set of device attributes and sends them to a backend server for analysis.

How the application works:

1. The app runs the fingerprint extraction process implemented in EXADPrinterLib.
2. The extracted attributes are compressed into a ZIP archive.
3. The archive is sent to a backend API endpoint for storage and analysis.

Installing the application

You can use the application in two ways.

1. Install from Google Play (recommended) Download the application directly from Google Play: https://play.google.com/store/apps/details?id=com.amiunique.amiuniqueapp

2. Build from source Clone the repository and build the application using Android Studio:

git clone https://github.com/AmIUniqueTools/AmIUniqueApp.git

Then open the project in Android Studio and build the app module.

• Build Prerequisites: To build the project from source, the following environment was used:

  Component	Version
  Android Studio	Android Studio Koala - 2024.1.1 Patch 1 -Build - #AI-241.18034.62.2411.12071903, built on July 10, 2024
  Java version	Java 8
  JVM	17.0.15
  Gradle	8.7
  Android Gradle Plugin	8.5.1
  Kotlin	1.8.0
  Compile SDK version	API 35
  ADB version	1.0.41

You can also download a prebuilt debug version of the application: app-debug.apk.

• app-debug.apk

3. Configuring the fingerprint collection endpoint If you want to collect fingerprints using your own backend, you can configure the API endpoint in two different ways.

4. Hardcode the endpoint in the source code: Edit the Retrofit configuration file RetrofitInstance.kt and replace the FALLBACK_URL with your server URL.

5. Provide the endpoint dynamically when launching the app: The application also supports passing the API endpoint via Intent parameters. Using adb:

adb shell am start \
-n "com.amiunique.amiuniqueapp/.presentation.MainActivity"\
--es API_END_POINT "YOUR_ENDPOINT_URL"

The API request is defined in FingerprintApi.kt. By default, the application sends fingerprints to:

<FALLBACK_URL>/saveFP/

To receive fingerprints, your backend must implement the same API schema.

📦 EXADPrinterLib

EXADPrinterLib is an Android library that implements the core logic used to extract device fingerprints following the EXADPrinter framework. The library collects a large set of device attributes accessible without requesting sensitive permissions, using three main techniques: Shell Command Execution, Java Reflection, and Content Provider Inspection. More details are provided in the Paper

The library is designed to be easily integrated into any Android application and provides a simple API to trigger fingerprint extraction and retrieve the resulting attribute set.

Below is a description of the key classes:

• FingerprintExtractor.kt:
  Contains the core logic for attribute extraction. It coordinates the three extraction techniques in the following order: executes shell commands, extracts SDK attributes via reflection, and finally queries content providers.

• ShellCommandsExplorer.kt:
  Manages the list of shell commands to execute and contains the logic for their execution.

• SDKExplorer.kt:
  Handles the inspection of Android native APIs via reflection. It begins by loading a JSON file of documented classes and initializing the InstanceFactory, which creates object instances. This process uses the SystemServiceFactory to access available system services via the Context class, after which it extracts fields and invokes methods.

• ContentProviderExplorer.kt:
  Responsible for querying a predefined list of content provider URIs and collecting their exposed values.

• InstanceFactory.kt and
  SystemServiceFactory.kt:
  Provide object instantiation logic for SDK classes and access to Android system services, respectively.

• FingerprintingUtils.kt:
  Contains utility methods used throughout the fingerprinting process.

• RootChecker.kt:
  Checks whether the device is rooted.

Installation

You can install EXADPrinterLib using one of the following methods:

1. Using Maven Central (recommended) Add Maven Central to your repositories if it is not already included:

repositories {
    mavenCentral()
}

Then add the dependency in your build.gradle file:

dependencies {
    implementation("io.github.amiuniquetools:exadprinterlib:1.0.0")
}

Replace with the latest available release.

2. Using the .aar file from GitHub Releases

• Download the .aar file from the project's releases page: https://github.com/AmIUniqueTools/AmIUniqueApp/releases
• Then follow the Android documentation to include an .aar dependency in your project: https://developer.android.com/studio/projects/android-library#psd-add-aar-jar-dependency

3. Building the library from source Clone the repository and include the library module in your project:

git clone https://github.com/AmIUniqueTools/AmIUniqueApp.git

Usage

Below is a minimal example showing how to initialize the different explorers and extract a device fingerprint using EXADPrinterLib.

import com.amiunique.exadprinterlib.ClassesJsonReader
import com.amiunique.exadprinterlib.ContentProviderExplorer
import com.amiunique.exadprinterlib.FingerprintExtractor
import com.amiunique.exadprinterlib.InstanceFactory
import com.amiunique.exadprinterlib.SDKExplorer
import com.amiunique.exadprinterlib.ShellCommandsExplorer

private lateinit var fingerprintExtractor: FingerprintExtractor

// ------------------------------------------------------------
// 1. Initialize the ShellCommandsExplorer
// ------------------------------------------------------------

// This component executes a predefined set of shell commands
// to collect system-level information (CPU, memory, network, etc.).
// If you want to customize the commands, you can pass your own commandsMap.
val adbExplorer = ShellCommandsExplorer()

// ------------------------------------------------------------
// 2. Load the list of Android SDK classes to explore
// ------------------------------------------------------------

// By default, the library loads a JSON file (classes.json) from assets
// containing a list of Android SDK classes to inspect via reflection.
val classesList = ClassesJsonReader().readFromAssets(applicationContext)

// Alternatively, you can provide your own class list file.
// Example:
// val classesList = ClassesJsonReader().readFromFile(File("/path/to/classes.json"))

// ------------------------------------------------------------
// 3. Create the InstanceFactory
// ------------------------------------------------------------

// InstanceFactory is responsible for creating instances of SDK classes
// when exploring them via reflection.
val instanceFactory = InstanceFactory(applicationContext)

// ------------------------------------------------------------
// 4. Initialize the SDKExplorer
// ------------------------------------------------------------

// SDKExplorer iterates over the list of classes and extracts accessible
// attributes and method outputs using reflection.
val sdkExplorer = SDKExplorer(instanceFactory, classesList)

// ------------------------------------------------------------
// 5. Initialize the ContentProviderExplorer
// ------------------------------------------------------------

// This component explores accessible Android Content Providers
// and extracts available data from them.
val contentProviderExplorer = ContentProviderExplorer(applicationContext)

// ------------------------------------------------------------
// 6. Create the FingerprintExtractor
// ------------------------------------------------------------

// FingerprintExtractor orchestrates all explorers and aggregates
// the collected attributes into a unified device fingerprint.
fingerprintExtractor = FingerprintExtractor(
    sdkExplorer,
    adbExplorer,
    contentProviderExplorer,
    applicationContext
)

// ------------------------------------------------------------
// 7. Extract the device fingerprint
// ------------------------------------------------------------

// The resulting fingerprint is a collection of attributes obtained
// from SDK reflection, shell commands, and content providers.
val fingerprint = fingerprintExtractor.extractFingerprint().toMutableList()