EFS encryption and decryption tips

I often see articles that encrypt files and folders. Most of them are installed with various software. If your system is WinXP/Win2003/2000, there is no need to encrypt them so much that you don’t need to install them. Software does not require cumbersome operations, because Windows itself integrates EFS (Encryption File System-EFS) encryption, which can encrypt files and folders on NTFS partitions! After encryption, it will equal all your files and folders. Locked into the safe, of course, don't worry about security, because it uses a 56-bit data encryption standard, so far no one can crack!

First, ESF encrypted files or folders < Br>

In order to improve the security of the file, Microsoft is in WinXP/Win2003/2000 (note that Windows XP home version does not support EFS encrypted file system), and introduced EFS encryption technology for NTFS. The EFS encryption operation is very simple. It is also transparent to the user of the encrypted file. After the file is encrypted, it is not necessary to manually decrypt it before use. Only the encrypter can open the encrypted file. After other users log in to the system, the encrypted file cannot be opened.

1. ESF Encryption Operation

For example, to perform ESF encryption on the test directory on the NTFS partition, you can do this: In WinXP, click “Start”/Programs/Attachments, Click to open “Windows Explorer", click “My Computer", open the NTFS partition, right click on the file or folder to be encrypted (eg test directory); then click “property>, at &ldquo On the General tab, click the “Advanced button; in the pop-up window, check the “Encrypt content to protect data” checkbox; click “OK" to exit.

If the folder is encrypted, a dialog box will pop up. You can choose to encrypt only this folder or encrypt the subfolders and files in this directory as needed; click to select After that, click the “OK" button and finally click “Apply”

So by default, you will find the EFS-encrypted file (folder), the color displayed in the Explorer will change to color, such as the color of the file/folder name in Figure 3. , not common black, but green, which means they have been encrypted by EFS.

The EFS encryption method for files is similar to the one described above. Now that we have an EFS-encrypted directory (for example, test), if you want to EFS-encrypt a file or folder in the future, you can also move them to that directory, which will be automatically encrypted.

Tip: Files and folders on the FAT partition cannot be encrypted by ESF. In addition, files marked as "System" attributes, files located in the Window system directory cannot be ESF encrypted.

2, timely backup key

ESF encryption operation is simple, but if you reinstall the system, even if you use the original username and password, you can not open the EFS encrypted file (clip) Therefore, you should back up the key in time so that you can open the encrypted file even after reinstalling the system.

Backup key method: In WinXP, click menu “Start” to run, type certmgr.msc to open the certificate manager, click “Certificate → Current User” under “personal &rarr ;Certificate", as long as the encryption operation has been done before, the right window will have a certificate with the same name as the user name. If there are multiple certificates, select “anticipate purpose" for “encrypt file system"; right click “ Certificate & rdquo;, select “ all tasks → export & rdquo; in the menu, then a "Certificate Export Wizard" window will pop up, select "Export private key" in the window, and follow the wizard's requirements, Enter the password to protect the exported private key, select the directory where the certificate is saved, and finally the certificate (the file with the CER suffix) and the private key (the file with the PFX suffix) are successfully exported.

For these backup keys (certificates and private keys), we can restore the encrypted data as long as we have a file. Other users can easily decrypt your encrypted files if you get your backup key, so be sure to keep your backup key.

Second, cancel EFS encryption skills

If you do not want to encrypt a file or folder EFS, you can cancel this: open Windows Explorer; right click on the encrypted file or file Folder, click <;Properties>; Click on “Advanced" on the "General" tab; in the pop-up window, clear the "Encrypt content to protect data" checkbox, and finally press “ OK & rdquo; Previous12Next page Total 2 pages