Microsoft KB Archive/230520

= HOW TO: Encrypt Data Using EFS in Windows 2000 =

PSS ID Number: 230520

Article Last Modified on 11/13/2003

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The information in this article applies to:


 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Professional

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This article was previously published under Q230520





IN THIS TASK

 * SUMMARY
 * ** Encrypting Data
 * Using the Cipher.exe Tool



SUMMARY
This article describes how to encrypt data using the Encrypting File System (EFS) in Windows 2000. The Encrypting File System (EFS) is the file encryption technology Microsoft uses to encrypt data directly on volumes that use the NTFS file system. You can use the encrypted data the same way you use non-encrypted data. In addition, you can configure permissions for your encrypted data to prevent unauthorized use. Someone who does not have the correct permissions receives an Access Denied error message if they try to open, copy, move, or rename an encrypted file or folder.

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Encrypting Data

 * 1) Right-click the Start button, click Explore, and then browse to the file or folder you want to encrypt.
 * 2) Right-click the file or folder you want, and then click Properties.
 * 3) Click Advanced, click to select the Encrypt Contents To Secure Data check box, and then click OK.
 * 4) Repeat steps 2-3 for each file or folder you want to encrypt.

NOTE: If you encrypt a folder, all the files and folders contained within the folder are encrypted.

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Using the Cipher.exe Tool
You can use the Cipher.exe tool to display or encrypt data at an MS-DOS prompt. To encrypt a file using the Cipher.exe tool, type a command similar to the following line at the MS-DOS prompt:

cipher [/E | /D] [/S:dir] [/I] [/F] [/Q] [dirname [...]]

The command line switches are defined in the following table. To view this information at the MS-DOS prompt, type cipher /? at an MS-DOS prompt.

Used without parameters, CIPHER displays the encryption state of the current directory and any files it contains. You may use multiple directory names and wildcards. You must put spaces between multiple parameters.

NOTE: EFS does not work on file that use the System attribute. Your computer could become unusable if you encrypt Windows system files. Also, note that EFS cannot be used on compressed files or folders. There are additional switches available with the command line utility Cipher.exe. To view them use the cipher /? command.

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Additional query words: compression

Keywords: kbenv kbhowto kbHOWTOmaster kbtool KB230520

Technology: kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Pro kbwin2000ProSearch kbwin2000Search kbwin2000Serv kbwin2000ServSearch kbWinAdvServSearch

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