How to encrypt/decrypt file or password in Linux?

• Types of Encryption methods-

1. GPG
2. Ccrypt
3. Bcrypt
4. 7-zip

•  Get all the require packages before you encrypt.

         

              $ sudo apt-get install gnupg bcrypt ccrypt p7zip-full

        

1. GPG

• To encrypt a single file

               $gpg -c filename 

             To encrypt data_info.txt file

   

             $gpg -c data_info.txt              //file will get saved as data_info.txt.gpg

              sample output

              Enter passphrase:   <your password>

              Repeat passphrase: <your password>

               //-c - Encrypt with symmetric cipher using a passphrase .
                         The default is CAST5.

•      To decrypt file using gpg command-

               $gpg data_info.txt.gpg

                sample output:

               gpg data_info.txt.gpg

               gpg:CAST5 encrypt data

               Enter passphrase:  <your password>

• To see list of the algorithms available-

              $gpg --version

           To use a different algorithm add for example: -crypto-algo

      

             $gpg -c -crypto-algo=3DES data_info.txt

• Decrypt file and write output to file document.txt u can use-

             $gpg data_info.txt.gpg -o docement.txt

  

    2. Bcrypt

• To encrypt with bcrypt use-

            $bcrypt data_info.txt     //file will b saved as data_info.txt.bfe

• To decrypt the file use-

            $ bcrypt data_info.txt.bfe

    3. Ccrypt

•  ccrypt command can be used in following ways:

1. by using ccrypt directly with either the -e (to encrypt) or -d (to decrypt) options
2. by using ccencrypt 

•   To encrypt a file-

            $ ccencrypt data_info.txt   //original file is replaced by data_info.txt.cpt

• To decrypt a file-

          $ ccdecrypt data_info.txt.cpt

    

      4. 7-Zip

• The 7-zip compression tool also incorporates AES encryption. To create an encrypted archive use the "-p" parameter with 7z command

           $ 7z a -p data_info.txt.7z data_info.txt    //you will be asked to
                                                                           enter password, then the 
                                                                          file will be compressed 
                                                                           and encrypted.