How to encrypt files with FinalCrypt

If you're looking for an encryption tool that offers a unique approach and a well-designed GUI, FinalCrypt might be just the tool.

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Image: Pixabay

You can never have enough security. And when you have data on your desktop that needs to be tucked under a layer of encryption, where do you turn? There are quite a lot of applications ready to take on this task for you, all of which promise to be the easiest, most secure option.

One such tool is FinalCrypt. FinalCrypt is an open source, cross-platform (Linux, macOS, Windows), and free GUI tool that makes encrypting files incredibly easy. I want to walk you through the process of installing and using FinalCrypt on a Debian-based Linux system (Elementary OS).

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What you need

The only things you need to successfully install and use FinalCrypt is a supported platform, a user account with admin privileges, and a file to encrypt. With those pieces at the ready, let's get to work.

Installation

If you're installing on either Windows or macOS, the installation is handled in the same way you install any application. For Linux, you'll want to download the installer file for your distribution (either RPM or DEB) and save it to your ~/Downloads directory. Open a terminal window and issue one the following commands:

  • For Debian-based distributions - sudo dpkg -i ~/FinalCrypt*.deb
  • For RedHat-based distributions - sudo rpm -ivh ~/FinalCrypt*.rpm

Once the installation completes, you'll find a FinalCrypt entry in your desktop menu. Click to start the newly installed application.

Encryption

FinalCrypt takes a different approach to encryption. Instead of working with a standard encryption key, you create a one-time pad key file for each instance of encryption. To create a one-time pad key file, click the Create Key button (Figure A).

Figure A

Figure A: Creating a one-time pad key file in FinalCrypt.

Note: The one-time moniker is a bit misleading. The pad files aren't used once and then discarded. Instead, each pad file created serves as a matching pair to the file it encrypts and decrypts.

In the resulting window (Figure B), give the new pad key file a name, select the file size, and click Create. You will not be prompted for a password for the creation of the pad key file.

Figure B

Figure B: Configuring the one-time file.

Next, select the newly created pad key file from the right pane in the FinalCrypt window (Figure C).

Figure C

Figure C: Selecting the pad key file for encryption.

With your pad key selected, it's time to choose the file (or files) you want to encrypt. This is done in the left pane. Navigate to the directory housing the file(s) and select it/them. To select multiple files, hold down the Ctrl or Shift buttons (in the standard fashion) and select your files. With the file(s) selected, click the Encrypt button. You can (optionally) add an encryption password to the file (Figure D). Do this before you click the Encrypt button, by typing the password you want to use.

Figure D

Adding a password to the encryption.


After you type the encryption password, hit Enter on your keyboard and then click the Encrypt button.

Decryption

What's unique about FinalCrypt is that you have to know which one-time pad file was used to encrypt the file. If you try to use the wrong file, you cannot decrypt. So obviously you want to name your pad key files in a way where you'll know which encrypted files it belongs to, but some random user wouldn't.

To decrypt that file, follow these steps:

  1. Open FinalCrypt.
  2. Navigate to (and select) the file to be decrypted in the left pane. Note: The encrypted file will include the .bit extension.
  3. Navigate to (and select) the necessary pad key file in the right pane.
  4. If you added a password to the encryption, type the password in the required field.
  5. Click Decrypt.

Once your file is decrypted, you can use it as you normally would. When finished, encrypt it (as you did earlier) with the necessary pad file, and your data is safe from prying eyes.

Use wisely

FinalCrypt takes a unique approach to encryption. If you use this tool wisely (making sure to not name your pad files in an obvious fashion), it will serve your encryption needs well.

Also see

By Jack Wallen

Jack Wallen is an award-winning writer for TechRepublic and Linux.com. He’s an avid promoter of open source and the voice of The Android Expert. For more news about Jack Wallen, visit his website jackwallen.com.