I'm not too worried about that -- this paper is "mirrored" on hundreds of university websites since it's a common reference for graduate courses in computer security.
If the course website was even on the open web to begin with. If they're in some university content management system (CMS), chances are that access is limited to students and teachers of that university and the CMS gets "cleaned" regularly by removing old and "unused" content. Let alone what will happen when the CMS is replaced by another after a couple of years.
https://wiki.archiveteam.org/index.php/University_Web_Hostin...