Cryptography: preferably level noobs, that is, it must begin with the basics of modular arithmetic, and to go further into deeper topics. Each Chapter needs to be exercises for the study of jobs and tasks for the full assimilation. How to be located tasks and themes in the best case:
It brow at the end of each topic there are exercises. After reading each topic you need to complete tasks, to secure reading material, tasks should be easy, can be a bit average. The length of topics from 3 - 10 p.
in the worst case:
in terms of design table of contents of topics and tasks - as lucky the main thing that was read in one breath.
About vector math, I have doubts. So who will be those where the themes do not start with University formulas. However, if anyone knows a tutorial on vector math, high school profile in-depth level such that I can approach.
Recurrence relations - it's all part of the discrete mathematics tutorial, so there is little chance that there will be a tutorial. But in any case, either the textbook or as a specific subject, it should be chewed in the smallest details. That is: from complex recursion formulae for very simple things it must come to be clear that hence, plus exercise.