Android™ How to Program, Second Edition

9.2.7. Getting a Private Key for Digitally Signing Your App

Before uploading your app to a device, Google Play or other app marketplaces, you must digitally sign the .apk file using a digital certificate that identifies you as the author of the app. A digital certificate includes your name or company name, contact information, etc. It can be self-signed using a private key (i.e., a secure password used to encrypt the certificate); you do not need to purchase a certificate from a third-party certificate authority (though it’s an option). Eclipse automatically digitally signs your app when you execute it in an emulator or on a device for debugging purposes. That digital certificate is not valid for use with Google Play, and it expires 365 days ...