In GNU/Linux, there are decent amount of tools with graphical interfaces that make file encrypting a breeze. However, there are also command-line based ones (few!) that let you easily encrypt/decrypt your data as well. Other than not having the ability to use the mouse (plus if you’re not a touch typist), most people don’t like command-line tools because they make you type a bit.
ccrypt is a utility for encrypting and decrypting files. It is based on the Advanced Encryption Standard, which is the U.S. government’s chosen candidate for the Advanced Encryption Standard . This cipher is believed to provide very strong security.
To install it run the following command:
$ sudo apt-get install ccrypt
To Encrypt the file run following command:
$ ccrypt myfile.mp3
You will be prompted to submit desired password to encrypt file which will be required to decrypt the file.
To Decrypt run following command:
$ ccrypt -d myfile.mp3
Using a “key-file” A key-file is sort of a long password that’s saved in plain text which is used for additional security. So let’s assume that I wanted to encrypted the above mentioned mp3 file using a key-file instead of a password. Then I’d use something like the below command (assuming the key-file’s name is “mykey” and both the key-file and the mp3 files are in my “Home” folder).
$ ccrypt -K mykey myfile.mp3
Now you can see the orginal file will be deleted and the encrypted with will be with .cpt extension.
When you want to decrypt the file just use the default decrypt command, and when asked, type the key-file with its path.
$ ccrypt -d myfile.mp3.cpt
And now see, your file is back.
Changing passwords or the key-file If you wanted to change the passwords or the key-file with ease (rather than decrypting and then re-encrypting it using a new password/key-file), then you can use the “-x” attribute.
For instance, if I wanted to change the password/key-file of the above mentioned mp3 file without decrypting it, then I’d use a command like the below one.
$ ccrypt -x myfile.mp3.cpt
When asked, first enter the old password and then the new one twice after that. That’s it!!!