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What is CrypTool-Online?


 Encrypt directly within your browser

CrypTool-Online provides an exciting insight into the world of cryptology. A great variety of ciphers, encryption methods and analysis tools are introduced, often together with illustrated examples. Our emphasis is on making explanations easy to understand with the goal to further the general interest in cryptology and cryptanalysis. Therefore, this website also provides applets to experiment with the introduced methods and to learn the principles in an interactive way.

You can learn the fundamentals of historically relevant ciphers in a little while (e.g. the Enigma, which significantly affected the progress of World War II), and also use the tools provided on this website to encrypt messages yourself. You can also decrypt and analyze already encrypted messages to educate yourself about the weaknesses of the different ciphers.

CrypTool-Online is the online version of the free e-learning program CrypTool. While CrypTool online is primarily intended for  studying  the fundamentals of classic ciphers, the download version of CrypTool is also suitable for working with longer texts and conducting high performance analyses on encrypted messages.


-    Ciphers (among others: ADFGVX, Alberti, Bifid, Caesar, Enigma, Four-Square, Freemason, Navajo, Nihilist, Playfair, Vigenère)
-    Coding methods (ASCII, Bacon, Base64, Code39, Huffman, Morse [you can listen, guess and learn])
-    Analysis tools (among others: Autocorrelation, Frequency analysis, n-gram analysis)
-    Highlights (among others: AES, Password generator, Password check, Matrix Screensaver)

Copyright © 1998 - 2017 CrypTool Project / Contributors