securing external portable firewire drives containing TIme Machine's backup directory

[Charlie Havens]

I am helping an organization develop a backup strategy for their  
traveling laptop users which would include issuing those users  
portable external Firewire drives to carry with them, using Leopard's  
Time Machine to backup to those portables, when on they are on road.  
Are those Time Machine files fully view able by anyone mounting that  
external drive. If so, should that external drive get lost or stolen,  
anyone could read those files. The question is whether there is a  
solution for external drive security, which would still allow Time  
Machine to access and use that drive, but would not make those files  
available to a casual thief?

Are there drives that have some sort of built in security to access  
the drive? Something where the drive would only work when attached to  
computers having certain MAC addresses? We would want it to include a  
list of MAC addresses, other than that particular user's laptop, as  
their laptop may fail or have a logic board replaced and then they  
would end up with a different MAC address, unrecognized by the  
external drive. A drive whose directory only mounts with a password,  
would also work. A drive where the security is built into the  
firmware of the drive, rather than software on the volume, might be  
more secure. Some thing similar to File Vault, but encompassing the  
root directory of the external hard drive? Am I asking for something  
crazy, or have I missed some security that is built into Leopard's  
Time Machine and I am mount the drive on machines were I already have  
read/write access.

Charlie Havens

Wooded Isle Computer Consultants,
5750 S. Stony Island Av., Chicago, IL 60637
Office 773-256-1099	Cell 773-848-0154	Fax 773-305-1916
charliehavens at mac.com       www.woodedisleconsult.com