Steps to encrypt/decrypt a file in Linux


When you send imported text or doc fies  or folders as a atachement by mail, you need to think about security. You should use encryption techniques for your important files or folders  to transferring data online or offline. ( by Mail, Upload your files some where, File or folder copied to USB etc ).

You can encrypt a single file or folder by using gpg command in Linux distributions. With this command encryption method is very easy, you need a password to decrypt a file or folder.

Now I will explain steps to encrypt or decrypt a file or folder in linux. GPG command can be found in almost all linux operating systems.  I am using CentOS Linux release 7.2.1511 (Core) operating system.

Here I will create a text file named as encryption-text-file under my home directory.


Step 1:  Open a terminal in your Linux distribution.

Step 2:  Use following command

gpg –symmetric  –cipher-algo AES256    encryption-text-file

when you will run this command , a new window will open where you  can set your password as shown in below image. For your password confirmation, you have to re-enter your password.


Now file will be saved as “encryption-text-file.gpg” . Here .gpg is encryption extension. You have sucessfully encrypted your file.

Step 3: Testing of Encryption

Now I will try to open this file using linux cat command.

[root@www]# cat encryption-text-file.gpg

É—æ-zží-ÈÖe@Ò±ø'¡a³TZY½J¦yècJr7ÂáÇ~¼év‘R&À””ªJ< ÉR*³Ò

You will not able to read this text because it is encrypted. 

Step 4: How to decrypt  a file?

To decrypt a text file you have to use again gpg command as explained below.

gpg -o encryption-text-file -d encryption-text-file.gpg

When I will run this command, a new window will open, where you have put password that was used during encrption process as show below image.


Your file is sucessfully decrypted your text file. For testing you can open file using cat command as explained below.

[root@www]# cat encryption-text-file

This is test file for Encryption and Decryption test.

Tip : Please use strong passwords during encryption process.