The following course is diving into math that Ethereum protocol builds on. It's a great recourse if you are interested in cryptography and protocol research. It assumes certain level of knowledge in mathematics and can be really demanding if you are not familiar with training in abstract algebra.
The content in this course is based around Eliptic curves over finite fields and their pairings, a book project by Matan, who is leading it. You can get started by reading up to chapter 3. Talks continue to introduce you to mathematics that requires understanding of symbols, logic, sets and other basics. When following a lecture, grab a paper or some fancy eInk maybe and sketch the content, exercises and your thoughts directly, that's how you learn .
You can also find the playlist of recordings of his previous course that dives into details from scratch. Our course is more condensed to focus on certain Ethereum specifics but still builds math from ground up.
There are many other books out there covering this content, you can always follow catch up on your math knowledge. Checkout this library and this list of books , especially these textbooks are helpful to cover our topics for beginners - Koblitz - Course in Number Theory and Cryptography, Rational points on Elliptic Curves and Pairings for Beginners, There is also MIT course, playlist covering similar content. For the most basic intro, you can always check numberphile
Needless to say, the advanced cryptographer is a good mathematician.