What book on the basics of cryptography would you recommend to students?

Question

Mathematics

Good day to all!
I ask for advice from experts in the field of cryptography. What book would you recommend to students of the specialty applied mathematics (1st year) to get acquainted with the basics?
Students have just begun their acquaintance with the mat. analysis, algebra, number theory.
It is desirable that the book be as simple as possible, introduce general principles without going too deep into implementation, and be not too thick so that its appearance does not discourage the desire to start reading. In other words, broaden your horizons.
And yet, they still can read books in English in a row.

Answer 1

Start with a book about XOR, or something ...

Answer 2

"Just Cryptography" by Victor de Castro. What you need to get acquainted and the volume of the book does not "scare" :)