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.
Land der Ideen - Statements
"This tool teaches in a very easy and touchy way, how to implement confidentiality, integrity and evidence (electronic signatures). Especially the understanding of electronic signatures will be of a very high importance for the time to come. Customers must understand this technology, otherwise there will be no trust or confidence in e-Government or e-Commerce, and the huge investments in these areas will generate no return."