What's the Name of That Book??? discussion

The book itself is fiction but is based upon an old cryptic text that exists in real life.

It is definitely written by two male authors.

It follows the lives of around 3 students at a large university in America (I think Stanford however may be Harvard or something similar) set on uncovering the mystery of the old text (I think it may be renaissance era).

I'm pretty stumped on details however there is a lecturer who has spent his career also trying to decode the script/paper/document and towards the end the book when one of the students start to make huge progress he tries to kill the student.
Eventually you think the student is killed however the book fast forwards to years later and the main protagonist receives a package with all the students work implying he is not actually dead.

I don't think the book is older than 1985.

This sounds exactly like The Rule of Four by Ian Caldwell and Dustin Thomason... Except that it was published much later, in the early 2000s.

YES!!!! That's it. Thank you so much! I have been going absolutely crazy trying to think of it.