Did you know?

That CrypTool was originally designed as an internal business application for information security training. CrypTool has since developed into an important open-source project in the field of cryptology. Over 50 volunteer developers worldwide contribute to the program.

What is CrypTool 1

CrypTool 1 (CT1) is an open-source Windows program for cryptography and cryptanalysis. It’s the most wide-spreaded e-learning software of its kind.

What is CrypTool 2?

CrypTool 2 (CT2) is an open-source program offering an innovative visual programming GUI to experiment with cryptographic procedures and to animate their cascades.

What is JCrypTool?

JCrypTool (JCT) is an open-source e-learning platform, allowing to experiment comprehensively with cryptography on Linux, MAC OS X, and Windows.

What is CrypTool-Online?

CrypTool-Online (CTO) runs in a browser and provides a variety of encryption and cryptanalysis methods including illustrated examples and tools like password generator and password meter.

What is MysteryTwister C3?

MysteryTwister C3 (MTC3) is an international Crypto Cipher Contest offering a broad variety of challenges, a moderated forum, and an ongoing hall-of-fame.

Humanity has concerned itself with the topic of cryptology for three thousand years. However, until the mid-20th century it was a topic of importance to only a small interested group -- diplomats and the armed forces. In any military conflict, exchange of confidential information and eavesdropping is crucial for survival. Due to the sensitive subject matter the vast majority of crypto research was done in secrecy in the past.

Humanity has concerned itself with the topic of cryptology for three thousand years. However, until the mid-20th century it was a topic of importance to only a small interested group -- diplomats and the armed forces. In any military conflict, exchange of confidential information and eavesdropping is crucial for survival. Due to the sensitive subject matter the vast majority of crypto research was done in secrecy in the past.

With the advent of the information age and the introduction of the internet for public use, new scenarios for cryptographic techniques became available, e.g.:

  • Encrypted connections and secure authentication for online banking
  • Encrypted communication in mobile phone networks
  • Encrypted and binding communication via e-mail
  • Electronic alternatives for a handwritten signature
  • Electronic protection of (intellectual) property (DVD, Pay-TV)
  • Car-theft protection systems (immobiliser)

Even though the above listing of non-military, commercially driven applications is incomplete, it demonstrates that today cryptology affects every member of the information society. Thus, research and teaching in the field of cryptology are of great importance.

At first the crypto research in the commercial sector has been performed with the public excluded. As a consequence of unpleasant experiences with the Security by Obscurity approach, companies gradually adopted the so-called Kerckhoffs' principle, which was already formulated in 1883.

The security of a cryptographic system must not depend on the secrecy of the algorithm. The security is only predicated on the secrecy of the key.

Meanwhile, by adhering to this principle, public research and teaching in the field of cryptology has become well-known and will be of even greater importance in the future. CrypTool provides an ideal environment for the learning of cryptologic history and the current state of crypto research and its applications. The CrypTool program and additional material can be used for self-study and in lectures.

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