To prevent the unauthorized use, alteration or falsification of protected content, a variety of cryptographic techniques can be used. Cryptographic techniques are particularly in the context of access and usage control. Digital signatures can ensure, for example, authenticity. The versions mentioned are also available as an upgrade from Windows XP, but each requires a new installation.
In the context of electronic payment systems, encryption methods (especially the Secure Electronic Transaction (SET) system) ensure secure transmission of sensitive billing information (such as credit card number) over the Internet as shown by a Cisco Configuration Manager.
Furthermore, symmetric authentication systems in the context of so-called challenge-response method to contribute to the identification and elimination (device revocation) of manipulated DRMS equipment and programs, thus making media against unauthorized use. The aim of the different watermarking techniques is to permanently combine certain information with a media product.