Android Security Architecture

1 min read Advanced Security Topics

Android Security Architecture

Android's security model is built on Linux kernel security, enhanced with additional layers specifically designed for mobile environments. Understanding this architecture is crucial for implementing effective security measures.

Multi-layered Security Model:

  • Linux Kernel: Provides process isolation and user-based permission model
  • Application Sandbox: Each app runs in its own process with unique user ID
  • Application Framework: Manages permissions and inter-app communications
  • Binder IPC: Secure inter-process communication mechanism
  • SELinux: Mandatory Access Control for additional protection

Android Permission System: The permission system controls app access to sensitive resources and user data. Modern Android versions have evolved this system significantly:

<!-- AndroidManifest.xml - Declaring permissions -->
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.secureapp">
    
    <!-- Declare only necessary permissions -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />
    
    <!-- Use permission groups for better user understanding -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    
    <!-- Declare custom permissions for inter-app communication -->
    <permission
        android:name="com.example.secureapp.PRIVATE_DATA"
        android:protectionLevel="signature"
        android:label="@string/permission_private_data"
        android:description="@string/permission_private_data_desc" />
        
    <application
        android:allowBackup="false"
        android:networkSecurityConfig="@xml/network_security_config">
        <!-- Application components -->
    </application>
</manifest>