Can you explain what digital signature verification means?

Application digital signature verification is the process of confirming the authenticity and integrity of an APK file. When publishing and installing an Android application, the system checks that the application is signed with the developer's key and that the content has not been altered after signing.

This ensures:

• Security — guarantees that the application is not tampered with and does not contain malicious code.
• Developer identification — allows the system and users to know who released the application.
• Updates — application updates must be signed with the same key for the system to allow their installation over the old version.

The verification process occurs automatically during application installation: Android compares the APK signature with already installed versions and checks the file's integrity.