On Apr 19, 2004, at 7:30 PM, yetty wrote: -- Redirected on behalf of Ye Wenxi -- Dear sir, Thank you for your advice. What I need is to access device from user space.I think the method of accessing any type of device should be similar. OK. Actually I will write a File Filter Driver. And in user space I want to access the driver and encode files. Actually I want to encrypt files. For example, now there are some files (such as test1.rtf and test2.txt and so on)in Users/Ye/documents/・, and normally everyone can open or read or write or save them. What I want to do is to protect them by command [Macintosh:/]Mary%crypt /Users/Ye/documents/ ・ After I input such command [Macintosh:/]Ye%crypt /Users/Ye/documents/・ the contents of the files (such as test1.rtf and test2.txt and so on) under folder /Users/Ye/documents/ will be encrypted. Therefore anyone else can not read the contents of the files unless I input the decode command. Could you use an encrypted disk image? MacOS X supports AES-128 encrypted disk images. You could mount one when you want its files to be available, and unmount it when you don't. _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.