Embodiments of the invention provide systems and methods for authenticating mobile device communications. A mobile device to which a message will be communicated may be identified. Based upon a shared secret between a service provider and the mobile device, a payload authentication code (“PAC”) may be generated, and the generated PAC may be associated with a payload for the message. The message and the generated PAC may then be communicated to the mobile device, and the mobile device may be configured to utilize the shared secret to verify the PAC and authenticate the message. In certain embodiments, the operations of the method may be performed by one or more computers associated with the service provider.