有限域

代码说明：

  通过上机操作，使学生对有限域的概念、性质及运算有一个充分的认识，为接下来现代密码学的学习打好基础。(Through the operation of the machine, the students have a full understanding of the concept, nature and operation of the limited domain, so as to lay a good foundation for the study of the next modern cryptography.)