Cipher
Applies To: Windows 7, Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2, Windows Server 2008, Windows Server 2008 R2, Windows Vista
Displays or alters the encryption of directories and files on NTFS volumes. If used without parameters, cipher displays the encryption state of the current directory and any files it contains.
For examples of how to use this command, see Examples.
Syntax
cipher [/e | /d | /c] [/s:<Directory>] [/b] [/h] [PathName [...]]
cipher /k
cipher /r:<FileName> [/smartcard]
cipher /u [/n]
cipher /w:<Directory>
cipher /x[:efsfile] [FileName]
cipher /y
cipher /adduser [/certhash:<Hash> | /certfile:<FileName>] [/s:Directory] [/b] [/h] [PathName [...]]
cipher /removeuser /certhash:<Hash> [/s:<Directory>] [/b] [/h] [<PathName> [...]]
cipher /rekey [PathName [...]]
Parameters
| Parameters | Description |
|---|---|
/b |
Aborts if an error is encountered. By default, cipher continues to run even if errors are encountered. |
/c |
Displays information on the encrypted file. |
/d |
Decrypts the specified files or directories. |
/e |
Encrypts the specified files or directories. Directories are marked so that files that are added afterward will be encrypted. |
/h |
Displays files with hidden or system attributes. By default, these files are not encrypted or decrypted. |
/k |
Creates a new certificate and key for use with Encrypting File System (EFS) files. If the /k parameter is specified, all other parameters are ignored. |
/r:<FileName> [/smartcard] |
Generates an EFS recovery agent key and certificate, then writes them to a .pfx file (containing certificate and private key) and a .cer file (containing only the certificate). If /smartcard is specified, it writes the recovery key and certificate to a smart card, and no .pfx file is generated. |
/s:<Directory> |
Performs the specified operation on all subdirectories in the specified Directory. |
/u [/n] |
Finds all encrypted files on the local drive(s). If used with the /n parameter, no updates are made. If used without /n, /u compares the user's file encryption key or the recovery agent's key to the current ones, and updates them if they have changed. This parameter works only with /n. |
/w:<Directory> |
Removes data from available unused disk space on the entire volume. If you use the /w parameter, all other parameters are ignored. The directory specified can be located anywhere in a local volume. If it is a mount point or points to a directory in another volume, the data on that volume is removed. |
/x[:efsfile] [<FileName>] |
Backs up the EFS certificate and keys to the specified file name. If used with :efsfile, /x backs up the user's certificate(s) that were used to encrypt the file. Otherwise, the user's current EFS certificate and keys are backed up. |
/y |
Displays your current EFS certificate thumbnail on the local computer. |
/adduser [/certhash:<Hash> | /certfile:<FileName>] |
Adds a user to the specified encrypted file(s). If used with /certhash, cipher searches for a certificate with the SHA1 hash specified. If used with /certfile, cipher extracts the certificate from the file name specified. |
/rekey |
Updates the specified encrypted file(s) to use the currently configured EFS key. |
/removeuser /certhash:<Hash> |
Removes a user from the specified file(s). The Hash provided for /certhash must be the SHA1 hash of the certificate to remove. |
/? |
Displays help at the command prompt. |
Remarks
If the parent directory is not encrypted, an encrypted file could become decrypted when it is modified. Therefore, when you encrypt a file, you should also encrypt the parent directory.
An administrator can add the contents of a .cer file to the EFS recovery policy to create the recovery agent for users, and then import the .pfx file to recover individual files.
You can use multiple directory names and wildcards.
You must put spaces between multiple parameters.
Examples
To display the encryption status of each of the files and subdirectories in the current directory, type:
cipher
Encrypted files and directories are marked with an E. Unencrypted files and directories are marked with a U. For example, the following output indicates that the current directory and all its contents are currently unencrypted:
Listing C:\Users\MainUser\Documents\
New files added to this directory will not be encrypted.
U Private
U hello.doc
U hello.txt
To enable encryption on the Private directory used in the previous example, type:
cipher /e private
The following output displays:
Encrypting files in C:\Users\MainUser\Documents\
Private [OK]
1 file(s) [or directorie(s)] within 1 directorie(s) were encrypted.
The cipher command displays the following output:
Listing C:\Users\MainUser\Documents\
New files added to this directory will not be encrypted.
E Private
U hello.doc
U hello.txt
Note that the Private directory is marked as encrypted.