A small piece of hardware connects to a mobile device and filters out attacks and malicious code. Using the piece of hardware, a mobile device can be protected by greater security and possibly by the same level of security offered by its associated corporation/enterprise. In one embodiment, a mobile security system includes a connection mechanism for connecting to a data port of a mobile device and for communicating with the mobile device; a network connection module for acting as a gateway to a network; a security policy for determining whether to forward content intended for the mobile device to the mobile device; and a security engine for executing the security policy.