Cryptography

I was trying to find a good resource for understanding the mathematics behind cryptography and came across Christof Paar’s cryptography series on YouTube. This is the best set of lectures on understanding the fundamentals of cryptography that I’ve found.
It’s 24 hours of video spread across a semester of classes so it will take a while to work through them, but they are worth the time. He does a great job teaching the math and reason for the math. Christof has a companion book available on crypto-textbook.com.