Are release signing key credentials required to set up expansion files?

Question

Are release keystore credentials required to create an expansion file for an Android app?

I wish to move larger assets into an expansion file (.obb) to bring the APK within the 100Mb limit Google Play imposes. These assets are videos and audio files in .mp4, .m4a, and .wav formats.

Answer 1

No, this is not an APK, it's just data (assets, audio...) so signing is not required since it doesn't get installed.

Answer 2

I'm assuming by "expansion file", you mean application functionality updates or you want to implement application changes then this answer is for you. & please do correct me if I interpret it wrong.

Yes! release Keystore credentials are required if you want to create an expansion (In terms of Application/ Functionality update). But, this is specifically required if you have uploaded the app on the play store.

Android Keystore system lets you store cryptographic keys in a container to make it more difficult to extract from the device. Once keys are in the Keystore, they can be used for cryptographic operations with the key material remaining non-exportable

So, from the above statement we can infer that it lets us,

1. Store cryptographic keys (private, public keys)
2. Perform cryptographic operations using stored keys (encrypt, decrypt, sign, verify, etc.)