AlphaShield is a hardware firewall that is connected between a user’s computer and their Ethernet network. I’ve seen these devices sold at Future Shop, Best Buy, Radio Shack and other retailers for a number of years but have yet to figure out why they would be useful.
Sure AlphaShield uses “IP Stealth technology” to make your computer invisible and can “block all 65,536 ports for both TCP and UDP communications”. But isn’t that what an off the shelf NAT router does? They also feature something called “Real Time Packet Authorization” (although I can’t find a technical explanation of what exactly that is). Sounds a little like Stateful Packet Inspection (SPI), a feature available on many of the better routers and firewalls out there.
I should note that a hardware firewall like the AlphaShield likely does not block outgoing packets and is not a full substitute for a software firewall running on the computer (like ZoneAlarm or any one of its many competitors). The AlphaShield does also feature an “auto disconnect” feature but that feature is also available in many software firewall programs.
In the end, the AlphaShield may provide some protection beyond that provided by a NAT router, but I’m not sure. The vendor’s website does not contain any detailed information that would allow a knowledgeable user to make an informed evaluation.