| 摘要 |
<p>A method comprising encrypting an original plain text file and making it available to a user as a protected file, and issuing to said user a user program and a user license to enable said user to decrypt the protected file and view an image of the original file while preventing the image of the original file from being copied to any file, other than as a further protected file. The image is preferably stored in a memory not backed up to the computer swap file. Preferably, the user program comprises an editor program and the user saves editorial changes to the original image in an encrypted difference file, separate from the original file. Both files are then used to re-create the edited image using the editor program and user license. The user program may comprise any computer tool including compilers. Alternatively, the user program comprises a special editor program incorporating an obfuscator which generates obfuscated code from the image generated by the editor program, so that this is only intelligible to a compiler or similar tool capable of converting the obfuscated code to an object file.</p> |
