Passwords on Folders

  • Thread starter Thread starter Sal
  • Start date Start date
S

Sal

Does anyone know what are the pro's and con's of using
passwords on folders? Also, does NT/windows 2000 allow
you to use passwords on folders?

I'm pretty sure using restrictions (Read, Write, Admin,
etc...) is the proper way to procedure but I would like
some insight on using passwords on folders if possible.

Thank you.
Sal
 
"Sal" said in news:[email protected]:
Does anyone know what are the pro's and con's of using
passwords on folders? Also, does NT/windows 2000 allow
you to use passwords on folders?

I'm pretty sure using restrictions (Read, Write, Admin,
etc...) is the proper way to procedure but I would like
some insight on using passwords on folders if possible.

Thank you.
Sal

Windows NT/2000/XP do not natively let you set passwords on folders. There
are products you can buy and install that will do that. For example,
ZipMagic loads as an installable file system and makes .zip files look like
folders (and you can password protect .zip files). That's just one way.

Setting permissions on folders and files is okay within the instance of
Windows under which those permissions were defined. If you yank the drive
out of the computer and plug it into another computer running Windows, most
of the permissions are ignored. I think the Administrator account uses the
same SID (security identifier) across all NT-based versions of Windows.
However, any permissions based on user accounts won't be obeyed. The SID
used to track permissions on a file as to which user has those permissions
won't be known on the computer to where you hauled the drive. Since this
other instance of Windows doesn't know about the SID, it cannot obey the
permissions based on that unknown SID. You can also take ownership of the
file so you can then delete the unknown SID and add your own permissions
under that instance of Windows. So permissions are good but only while the
drive is still under the instance of Windows where the SIDs were defined
upon which those permissions were based. I suppose you could copy the SAM
(Security Accounts Manager) file to the other computer but you would be
sacrificing the SAM that was already there on that new computer (I haven't
heard of a mans of merging SAM files).

For best protection, use NTFS on your hard drives so you can then EFS
(Encryption File System). You can even configure EFS to allow only your
account to be able to read the folder and files and not let the
Administrator read them. Administrator could still take ownership or modify
permissions but it couldn't read the contents of the files. Be sure to
export your EFS security certificate. If you move that drive with
EFS-protected files to another computer (i.e., under a different instance of
Windows that doesn't have your EFS certificate), or if you restore
EFS-protected files from a backup onto a different computer, then you need
to import your EFS certificate so you can read those EFS-protected files
over there. If you don't export the EFS certificate, you have basically
locked the files and thrown away the key, so hopefully that instance of
Windows never has to be reinstalled or you don't have to move or restore the
EFS-protected files to another and different instance of Windows.

EFS is the way to go if you want to prevent anyone but yourself to read the
contents of your files even if you move the files to a different Windows
host or have to reinstall Windows and restore your files. Never EFS protect
the system files (i.e., don't apply EFS to %windir% or any subdirectory).
There's no point to EFS protect executable files (i.e., .exe) unless the
program is your own creation and you don't want anyone else to execute it or
disassemble it. EFS incurs a slight penalty in time due to the delay to
decrypt the file's contents.
 
Some additional help regarding EFS:

Encrypting Files in Windows 2000
http://support.microsoft.com/?kbid=222054

Step-by-Step Guide to Encrypting File System (EFS)
http://www.microsoft.com/windows2000/techinfo/planning/security/efssteps.asp

Cannot Gain Access to Previously Encrypted Files on Windows 2000
http://support.microsoft.com/?kbid=221997

HOW TO: Encrypt Data Using EFS in Windows 2000
http://support.microsoft.com/?kbid=230520

HOW TO: Back Up the Recovery Agent Encrypting File System Private Key in
Windows 2000
http://support.microsoft.com/?kbid=241201

HOW TO: Restore an Encrypting File System Private Key for Encrypted Data
Recovery in Windows 2000
http://support.microsoft.com/?kbid=242296

The Local Administrator Is Not Always the Default Encrypting File System
Recovery Agent
http://support.microsoft.com/?kbid=255026

There are lots more KB articles at Microsoft's support site
(http://support.microsoft.com/). You might also look at the included help
(Start -> Help).
 
Good reply Vanguard. I just want to add two points.

1. The built in administrator may be able to decrypt the files if he is the
recovery agent which he would be on a default installation of W2K on a non
domain computer [there is also a recovery agent for a domain]. Windows XP
Pro does not have a recovery agent by default.

2. Excellent advice on exporting the certificate - just as long as the user
exports the associated private key which is needed for decryption. The user
may at times want to delete the private keys [user and recovery agent] also
during an export when their computer is not physically secured such as a
laptop, otherwise the encrytpion is only as safe as their password, which
might be guessed or cracked. --- Steve
 
Back
Top