Reddit mentions of Foundations of Cryptography

I would start with Cover & Thomas' book, read concurrently with a serious probability book such as Resnick's or Feller's.

I would also take a look at Mackay's book later as it ties notions from Information theory and Inference together.

At this point, you have a grad-student level understanding of the field. I'm not sure what to do to go beyond this level.

For crypto, you should definitely take a look at Goldreich's books:

Foundations Vol 1

Foundations Vol 2

Modern Crypto

Katz and Lindell is the undergrad gold standard on intro cryptography. Goldreich is a good graduate-level intro if Katz and Lindell is too basic. Goldreich also has a second volume.

Introduction to Modern Cryptography & Foundations of Cryptography(+volume 2)

Oi. Disclaimer: I haven't bought a book in the field in a while, so there might be some new greats that I'm not familiar with. Also, I'm old and have no memory, so I may very well have forgotten some greats. But here is what I can recommend.

I got my start with Koblitz's Course in Number Theory and Cryptography and Schneier's Applied Cryptography. Schneier's is a bit basic, outdated, and erroneous in spots, and the guy is annoying as fuck, but it's still a pretty darned good intro to the field.

If you're strong at math (and computation and complexity theory) then Oded Goldreich's Foundations of Cryptography Volume 1 and Volume 2 are outstanding. If you're not so strong in those areas, you may want to come up to speed with the help of Sipser and Moret first.

Also, if you need to shore up your number theory and algebra, Victor Shoup is the man.

At this point, you ought to have a pretty good base for building on by reading research papers.

One other note, two books that I've not looked at but are written by people I really respect Introduction to Modern Cryptography by Katz and Lindell and Computational Complexity: A Modern Approach by Arora and Barak.

Hope that helps.