Purpose of APK Signing

Authentication: When you sign an APK file, you attach a digital signature to it using a cryptographic key. This signature serves as proof that the app has not been tampered with and that it comes from a trusted source. Users and Android devices use this signature to verify the app's legitimacy.

Integrity: The signature also ensures the integrity of the APK. If any changes are made to the APK after it is signed, the signature becomes invalid. This prevents malicious parties from modifying the app's code or resources.

Updates: When you release updates to your app, you must sign them with the same key as the original APK. This allows users to update the app without losing their data or settings.