Math, peers. . There are even fewer people in the Journal of Cryptography. Relatively speaking, the difficulty of the exam lies in the specialized courses. Generally, a better school has this major, and the employment is not very extensive. It is not recommended to apply. The key is whether you can learn pure theory courses well, and it is recommended to apply carefully. In fact, the mathematics major itself can take the postgraduate entrance examination and get into the university. You can apply for a teacher at a university. I just take a master's degree and then take the civil service exam.