## About Digital Signatures

In order to proove that a message was really sent by the alledged sender the concept of Digital Signatures has been invented. As the name says a message is digitally signed by the sender. By this signatures one can check the authenticity of a message. Using this will reduce the risk for trojan horses (a message that claims to be a patch to a certain problem but actually contains a virus or does something with data on your computer). Also information or data can be verified as comming from a legitimate source and thus be regarded as be real.

A digital signature is made through a combination of the secret key and the text. Using the senders public key the message can be verified. Not only will be checked if the correct sender is involved, also the content will be checked. So one knows that the message comes from the sender and has not been changed during the transportation process.