Create a read-only file

Question

I was wondering wether it is possible to create or simulate a file with a content set at creation and the assurance that nobody can ever change the file. If possible, can I

Answer 1

Setting a file to read only is not going to make it so no one can ever change it. It takes about 3 seconds to unset the read only flag. The file can then be opened in a hex editor or other program that can handle the file type and changes can be made.