A developer’s cryptographic signing key is one of the major linchpins of Android security. Any time Android updates an app, the signing key of the old app on your phone needs to match the key of the update you’re installing. The matching keys ensure the update actually comes from the company that originally made your app and isn’t some malicious hijacking plot. If a developer’s signing key got leaked, anyone could distribute malicious app updates and Android would happily install them, thinking they are legit.
On Android, the app-updating process isn’t just for apps downloaded from an app store,
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