Lock a USB Drive with 10.6.8

Try TrueCrypt which encrypt all the data within it

http://truecrypt.sourceforge.net/OtherPlatforms.html

You could start with your backup/working OS X 10.6.8 on a locking USB flash drive

https://www.google.com/?gws_rd=ssl#q=usb+flash+drive+with+lock+switch

to see products or purposed use of these by maker names use search engine

Good luck! 😐

There may be some security options in OS X Disk Utility, but to

avoid a File Vault if possible should you forget the password;

and usually a bootable full running OS X could have Security

settings in System Preferences engaged, not an external file.

You may be able to encrypt the entire content, not sure how

because after hearing horror stories of lost access to very

important files or drives, or partitions, I've not bothered; as

a single user there are other ways to lose file access that do

not involve setting up these concepts. Backups to secure a

working copy of ones archive and to have a bootable clone

are better goals to overcome other kinds of loss.

Physical access to the computer and media are the first level

of security; then passwords, then encryption, as/when needed.

While they likely do not provide a simple path to your needs

the security guides in .PDF download document form, from

Apple Support may be helpful as they cover Mac OS X 10.3

through 10.6.8.

•Security Configuration Guides - Apple Support

(Mac OS X: 10.3/10.4/10.5/10.6)

https://ssl.apple.com/support/security/guides/

Hopefully you can find a workable security measure for use

with a USB flash drive to password protect its content.

Good luck & happy computing! 😐

Another idea, if you looked into proprietary means of securing files on a USB

Flash drive, such as SanDisk has for their own product line, 'SecureAccess'

software, this allows a file on the USB or SD or other memory card security

over one folder, not the entire card.

about sandisk folder security product - i've never tried it:

http://www.sandisk.com/products/software/secureaccess/

A bootable volume on a USB flash drive or other solid state device, may not

be able to work from a folder that has this kind of security layer, first. So that

does limit what can be used from such a concept; depending on the purpose.

Those other means of protecting the USB flash, include previous mentioned

where there are ideas online to sift through; some likely won't suit your purpose.

So there are several bits of topic to sort through, sadly most is advertising:

https://www.google.com/?gws_rd=ssl#q=usb+flash+drive+password+protect

The idea such as sandisk suggests may be an OK idea, along with other means

to secure the actual USB flash drive, to help limit access to files on there.

Good luck, in any event! 😐