CrypToolEver wondered how encryption algorithms work? What do algorithms like AES or Twofish do, and how did they encrypt in the past? How did Julius Caesar encrypt his messages to protect them, or how did the German Enigma machine work?
Of course there are many books available online, but maybe many of you want to experience the experience firsthand.
CrypTool is one free program for Windows. There is also one available version called JCryptTool cross-platform which requires Java to run. With the app you can better understand and visualize encryption algorithms.
The main interface (UI) displays various options for booting. As a first time, the best way to get started is with the wizard provided by the program. The program will "travel" you to the world of encryption and teach you encryption, decryption, fragmentation functions, or crypto-analysis.
If you choose encryption and decryption, for example, you will be asked to choose between classical or modern. Classical encryption lists nine algorithms used in the past by Caesar and Vigenere in Enigma and Playfair.
Each algorithm is briefly explained to know how it works. You can then try to enter some text you want to decrypt yourself. Both the original message and the decrypted text will be displayed on the last screen.
The software supports symmetric and asymmetric modern algorithms. It does not explain them too thoroughly and you may need to consult documentation where each algorithm is explained in detail.
The same goes for the Hash functions it supports (MD5, SHA-256, RIPEMD160 and others).
The second major feature of CrypTool is the playground . Here you can create worksheets to test them algorithms encryption or hash functions.
You can also try the application yourself. CrypTool is a very good educational program not only for computer science or for students of mathematics, but also for anyone interested in cryptography.
CrypTool 2.0 (Stable Build 6222.1)
