上传基础数论两本，基础数论的研究对象是自然数尤其是素数，研究核心是同余式，对密码学感兴趣的同学可以看一下(The two number of basic number theory is uploaded. The natural number, especially prime number, is the research object of the basic number theory. The core of the study is congruence, and students interested in cryptography can have a look.)