A method of destroying file contents of a file includes storing the file in a predefined file format; integrating an algorithm that destroys file contents and has predefined trigger criteria into the file; checking the predefined trigger criteria when the file is opened; destroying file contents if at least one predefined trigger criterion is satisfied; and modifying the integrated algorithm if the predefined trigger criteria are not satisfied, wherein a first part of the algorithm is integrated into a first part of the file called by an executing program or an executing operating system when the file is opened, and modifying of the integrated algorithm includes modifying the storage structure of the algorithm so that it occurs in changed form after the opening of the file and cannot be recognized as before.