System and method for controlling devices using short message service via a relay device

Abstract

Described are systems and methods for responding to a lost-mode command directed to a target wireless device from a server to alter the functionality of the device, such as to restrict access to sensitive data. A relay device is selected at the server to act as intermediary between the server and the target wireless device. An encrypted message with both the lost-mode command and the relay-device phone number is relayed to the target wireless device. The target wireless device decrypts and parses the message to extract the lost-mode command and the relay-device phone number. To authenticate the relay device as the intended sender of the lost-mode command, the target wireless device compares the phone number of the message sender to the relay-device phone number specified in the message. The target wireless device disregards the lost-mode command if the sender's phone number does not match the relay-device phone number, and otherwise enters a 'lost mode.'