A method of preventing internet hacking of web sites. Operating system component files are encrypted by first selecting a secret key which is randomly inserted into the contents of the source file. The file is then encrypted using a second, separate key. When the encrypted OS file is subsequently requested by the operating system, it is decrypted and the decrypted file searched for the second key. If the second key is found, the file is considered valid and is processed by the operating system. If the second key is not found, the file is considered invalid and is not processed.