A major concern for many developers when evaluating App Engine (or any platform) is application security. Developers need control over which services are available to which consumers. Minimizing access where possible reduces a system's overall attack surface. App Engine provides a number of mechanisms for restricting access to services. Many of these methods can be combined to quickly build a powerful security layer on top of your App Engine services.
Networking and security
The App Engine firewall
Perhaps the simplest method to secure App Engine services is through the use of firewall rules. The App Engine Firewall allows developers to define up to 1,000 unique firewall rules over which IP address ranges may or may not...