Using one publishing key on two accounts in Android Market

Question

Are there any downsides to using the same signing key for publishing apps under different Android Market accounts? (Different apps under each account.) Likewise, are there any problems in using different signing keys for different apps in the same account? I would assume not in both cases, but I couldn't find anything definitive posted about this. So I thought it prudent to ask if anyone knows for sure.

Answer 1

It depends totally on your needs, so let's see different needs,

Why using same key for different apps?

• If you want to use App modularity features (as recommended by the official documentation):

  Android allows apps signed by the same certificate to run in the same process, if the applications so requests, so that the system treats them as a single application. In this way you can deploy your app in modules, and users can update each of the modules independently.

• If you want to share Code/Data securely between your apps through permissions (also as recommended by the official documentation):

  Android provides signature-based permissions enforcement, so that an app can expose functionality to another app that is signed with a specified certificate. By signing multiple apps with the same certificate and using signature-based permissions checks, your apps can share code and data in a secure manner.

• If you want to avoid the hassle of managing different keys for different apps.

Why using different keys for different apps?

• If you are somehow paranoid about security (and you should), not to put all the eggs in one basket, which is highly recommended in this article.

• If the apps are completely different & won't ever use the app-modularity or Code/Data sharing described above.

• If there is even a small chance that you will sell one of the apps separately in the future, then that app must have its own key from the beginning.

I wrote an article about it.