Trusted Device Criteria

To ensure the security and proper functionality of the tapXphone, the following criteria must be met for a device to qualify as trusted:

Device State Requirements

The device must not:

1. Have an Unlocked Bootloader:

   • The bootloader must be locked.

   • For more information on locking the bootloader, see here.

2. Be Rooted:

   • The device must not have root access (the user must not have root privileges).

3. Have SELinux Disabled or Permissive:

   • SELinux must be set to "enforcing" mode. Devices with SELinux in "disabled" or "permissive" mode are not secure and will be blocked.

   • For more information on SELinux in Android, see here.

   • How to check:

     • Certain devices, such as Samsung smartphones, allow users to check the SELinux mode manually. To verify the SELinux state:

       1. Go to Settings > About Phone.

       2. Find the section Software Information (or similar).

       3. Look for SE for Android or a similar entry. The SELinux mode should be listed as either Enforcing or Permissive.

          • If it shows Enforcing, the device is secure and compliant.

          • If it shows Permissive or Disabled, the device needs adjustment or replacement.

   • If a device is flagged due to SELinux misconfiguration, the following options are available:

     1. Adjust SELinux Mode Manually: Advanced users may attempt to change SELinux mode from "permissive" or "disabled" to "enforcing." Warning: This process involves significant system modifications and could render the device unusable. It is not recommended for non-experts.

     2. Visit a Service Center: You may seek assistance from a professional service center. Specialists at these centers may be able to reconfigure SELinux settings or provide a resolution.

     3. Change the Device: The most straightforward and reliable solution is to replace the device with one meeting security requirements, where SELinux is properly enforced.

4. Be in Developer Mode:

   • How to check:

     • Method 1: Open "Settings," go to "About phone" or "About tablet," find the "Build number" section (or "MIUI version" on Xiaomi devices), and tap it. If developer mode is enabled, you'll see a confirmation message.

     • Method 2: Open "Settings," select "For Developers" (or "Advanced > For Developers"), and ensure the "Developer Mode" switch at the top is turned off.

5. Be in Debug Mode:

   • How to check:

     • Method 1: Open "Settings," select "For Developers" (or "Advanced > For Developers" on some devices). In the "Debug" menu, ensure "USB/Wi-Fi Debugging" is not activated.

     • Method 2: Connect the device to a computer and ensure no "USB/Wi-Fi Debugging enabled" notification appears on the smartphone.

6. Pass Google Play Integrity API Checks:

   • The device must successfully pass the Google Play Integrity API check with the MEETS_STRONG_INTEGRITY status.

   • How to check:

     • To verify the integrity verdict on your device, follow these steps:

       1. Enable Play Store's developer options by tapping your profile icon in the Play Store app, then selecting Settings.

       2. Open the About menu and tap Play Store version seven times to unlock developer mode.

       3. Open the Play Store app, tap your profile icon, then go to Settings > General > Developer options.

       4. In the Play Integrity settings, tap Check integrity to generate the verdict for the device.

     • For more detailed instructions, see here.

7. Contain Apps Violating Google's Software Principles:

   • Apps installed on the device must comply with Google's Software Principles and Unwanted Software Policy.

   • How to check Google Play Protect status: see here.

Application Installation Source

• The application must be downloaded and installed only from the Google Play Store.

• Installation from other sources is strictly prohibited, as it violates the License agreement.

Safe Usage of the tapXphone

When using the tapXphone, the user must not:

1. Allow Screen Overlays:

   • Apps or system functions (e.g., messengers) that overlay the tapXphone screen must be turned off during transactions.

   • If a message about restricted usage appears, follow the steps here.

2. Use Split Screen or Broadcast Modes:

   • Do not activate split-screen mode or use broadcast functionality from the mobile device.

3. Use the Camera in Unintended Ways:

   • Background apps with camera access must be closed during a transaction.

   • Disable system functions that keep the screen active due to constant background camera usage (e.g., Face ID features).

4. Take Screenshots or Record Videos:

   • Screenshotting or screen recording is prohibited while using the application.

5. Turn Off Previously Granted Permissions:

   • Ensure that all required permissions remain active for the application.

6. Use Remote Control Applications:

   • Applications like TeamViewer or AirDroid are not allowed.

NFC Requirements

The device must have:

1. A functional embedded NFC module.

2. NFC configured to read cards.

   • How to check:

     • Open "Settings," go to "Connection and Sharing," and ensure NFC is turned on.

     • If there is an option to choose between "SIM" and "e-wallet," select "e-wallet."

Security Recommendations

• OS Updates: Regularly update the device’s OS and components to ensure the latest security improvements.

• Trusted Apps: Only download apps from trusted vendors in the Play Store, verified by Google Play Protect.

• Malware Detection: Install and update malware detection tools to protect the device.