CrypTool is a very interesting tool for Windows, but it also exists jCrypTool based on Java and that we can run on Linux, for which we do not use the Microsoft operating system. With it we can learn about cryptographic processes.
We know that there are many tools to encrypt and decrypt data, but not many know about how data encryption and decryption occurs. Therefore, jCrypTool is highly recommended for learning about cryptography and experimenting with cryptographic algorithms.
With her we will learn the process data encryption graphically so that any user can easily understand the process. jCrypTool supports various encryption algorithms, old and modern, information about them and interacting with them.
The application is free and open y can be obtained from the project website (cryptool.org) or from other sources, such as sourceforge.net or github.com. Once you download the appropriate tarball that you will find in the link that I leave you, you must unpack it. Once unpacked, just double-click on the JcrypTool icon inside and it will open (obviously we will need to have Java installed).
More information - Cryptography Tutorial