Method for monitoring and saving data records in a monitored system (100) with the purpose of preventing the possibility to tamper with said data records at a later time. The inventive method comprises the steps of saving data content together with a time-limited active key and encrypting the data content...http://www.google.com/patents/US20060053294?utm_source=gb-gplus-sharePatent US20060053294 - System and method for proving time and content of digital data in a monitored system
