It's no surprise these days when a security vendor gets cash, but this one's using it in a unique way.

Bluefire Security Technologies, which just got $6 million in second-round funding from JK&B Capital, is building firewall and intrusion-detection software for handheld devices, including mobile phones, PDAs, and tablet PCs. Bluefire is developing technology to get memory-intensive, complex firewall software onto small form factors.

Remote end-point security has been neglected, says Matthew Kovar, a Yankee Group analyst. Even at companies that have adequate security, "when users bring laptops home, that security is lost," Kovar says. Handheld devices are even less secure.