A great application for newcomers as well as for the experienced to learn more about various cryptographic protocols and algorithms. CrypTool provides an intuitive graphical interface to play around with various settings of any cryptographic algorithm. Using the tool, one can understand the importance of key length and choice of characters for any encryption scheme.
It is a great application for getting started into cryptography and cryptanalysis. Although the application might look a bit complicated at first, once you figure out how to put the pieces together, am sure you’ll have fun learning !
The application is available for Windows, Linux and Mac. They also offer an online portal which can be accessed here. Hope you enjoy and learn more about cryptography using this free tool.