CrypTool is a free and open tool, thanks to which anyone interested can get acquainted with the operation of algorithms and cryptographic protocols. The program enables e.g. encryption and decryption with the use of modern solutions such as AES, but also the testing of classical ciphers such as Caesarean key.

The tool also allows for cryptographic analysis. The application uses a ribbon known from Microsoft Office in its interface, so it should be easy to use. By default, a wizard is launched, thanks to which we can select the operations we are interested in.

They have been grouped into coding / decoding (including encryption), cryptanalysis, shortcut functions, mathematical functions, various types of code, as well as additional tools. Thanks to CrypTool we can learn classical algorithms such as: Caesar's cipher, Vigenere, XOR, Scytale, Enigma, ADFGVX and Transposition.

The application also enables checking much newer, currently used solutions such as AES, DES, SDES, Twofish, TEA and RC2, as well as asymmetric solution in the form of RSA. The program allows you to precisely configure the parameters of algorithms and input data, in addition to the wizard also allows you to design circuits dealing with cryptography (e.g. downloading data from the camera, their encryption, etc.).

You can use MD5, SHA-1, SHA-256, RPEMD160, Tiger and Whirlpool among the available shortcut functions. CrypTool also offers the possibility of encoding text between different formats, e.g. from ASCII to Base64, from UTF-32 to binary values, etc.

It is even possible to check the Morse code. Additional tools built into the program allow you to quickly secure the password (encryption with AES), check their strength on the basis of various determinants such as entropy, KeePass, Mozilla, etc. In additional tools we will also find a sub-programme for analyzing servers to vulnerability of Heartbleed vulnerability, as well as generating random numerical strings.

The application allows you to use OpenCL, install additional components and configure settings. A Polish language version is also available.