Securing mobile devices will become particularly important as dual-mode cellular/Wi-Fi handhelds hit the streets. Closed cellular networks are pretty secure. However, once a dual-mode device starts sniffing around for an open Wi-Fi network, too, extra security measures are necessary.

Last week, I mentioned a possible solution: application virtualization. This option keeps your client software and data in the data center so you just send screen shots across the wireless WAN (and/or Wi-Fi LAN). This way, there’s no data on the device to compromise.

Other alternatives continue to emerge. For example, Sprint announced at the Interop trade show and conference last week a mobile security service that works across any wireless carrier’s network. The service reportedly enforces password policies and allows individual files (or an entire device) to be encrypted using Advanced Encryption Standard (AES) or Triple-DES.

The Sprint Mobile Security service, based on technology and products from enterprise mobility security company Mobile Armor, reportedly also scans for malware attempting to infect devices via text messages or Bluetooth connectivity. The service also includes a firewall to restrict access based on source, destination, port and application.

Firewall options for mobile handheld devices are also emerging from the likes of McAfee and Trend Micro.

Meanwhile, earlier this month, a draft specification for stronger mobile security based on hardware protection was released by the Trusted Computing Group’s Mobile Phone Work Group. It’s called the Mobile Trusted Module (MTM) Specification, and OEMs, silicon vendors and others can use it to develop chips for mobile devices.

The mobile security spec aims to ultimately help mobile users do the following:

* Ensure the device is running authorized software and hardware.
* Ensure that the correct user and device are accessing appropriate services.
* To verify that software downloads are trusted.
* Protect user data and privacy.

The spec includes provisions, for example, for a channel for secure transfers between a device’s Subscriber Identification Module (SIM) card and UMTS Integrated Circuit Card (UICC). A primary reported goal here is to provide users with a secure channel for storing sensitive data on the UICC and then allow them to safely move that data between devices.

MTM’s utility will depend on the spec actually getting implemented into devices that users buy.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.