We have just announced the implementation of a license server for the Android Market app store. This innovation is our response to one of the complaints that we constantly hear from the Android developer community.
Intentions and consequences, as follows from the announcement, are quite transparent. If you want to use the license server in your application, it is best to start by reading the official documentation:
Licensing Your Applications . Here I would like to highlight some technical details:
- This feature is built into the client application of the Android Market since version 1.5, therefore you should not worry about the availability of the latest version of Android
- It is safe, based on a public / private key pair technology. Your request to the server is signed by the public key, and the response from the server is signed by the private key. For each developer account, there is a single public / private key pair.
- Your application will not communicate directly with the license server; all you need to do is communicate with the Android Market client using IPC (Inter-Process Communication), which will be in direct communication with the server.
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- Sufficient tools are available that will be supplied with the SDK - LVL (License Verification Library, version checking library). It provides entry points for sending a request to the server and processing the result. In addition, it includes several ready-made modules that you can use to implement various license verification policies.

- The LVL library comes in the form of a library project source for Android. Together comes the shell for testing.
- In the developer part of the Android Market there is a web-interface for managing keys, both for testing and for release.
- It is clear that you can not access the server when the device is offline. In this situation, the choice is yours; one of the possibilities is caching the status of licenses, and LVL provides the module already assembled for such situations.
- We believe that this is the most significant innovation to protect against copying at the moment and look forward to a reaction from the developers.
Translation of an
article published by Tim Bray in the official blog of Android Developers