java实现仿射密码加密解密

本文实例为大家分享了java实现仿射密码加密解密的具体代码，供大家参考，具体内容如下

加密：将明文转化为对应的数字，如 ‘a'-> 0, ‘b'->1,…,'1'->26,'2'->27,…然后将数字进行仿射运算，求取出来的数字再转化为字符。即 密文=(K1*明文+K2)mod36

解密：密文转化为对应数字，然后进行仿射的逆运算，得到对应数字，然后将其转化为字符明文。解密 K3是K1的乘法逆元

import java.util.Scanner;

public class Affine{
public static void main(String[] args) {
char[] form = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0'
 , '1', '2', '3', '4', '5', '6', '7', '8', '9'};
Scanner sc = new Scanner(System.in);
System.out.println("请输入待加密的明文：");
String MingWen = sc.nextLine();
MingWen=MingWen.toUpperCase();//将输入的明文全部大写
final int K1 = 103;
final int K2 = 103;
final int K3 = 31;
int [] cipherNum=new int[MingWen.length()];//用来存储数字化的密文
encryption(MingWen,form,K1,K2,cipherNum);
decryption(form,MingWen,K2,K3,cipherNum);

}
public static void encryption(String MingWen,char[] form,int K1,int K2,int[] cipherNum){
//第一步：将明文存入数组
char[] pla=new char[MingWen.length()];
for (int i = 0; i <MingWen.length() ; i++) {
 pla[i]=MingWen.charAt(i);
}//已将明文存入字符数组pla中
//第二步：通过脚标找到明文中每个字符对应的数，参与加密运算
int[] MingWenNumber=new int[pla.length];
for (int i = 0; i <pla.length ; i++) {
 for (int j = 0; j <form.length ; j++) {
 if (form[j]==pla[i]) {
  MingWenNumber[i] = j;
 }
 }
}
//通过脚标将明文全部转化为数字
char[] cipher = new char[MingWen.length()];//cipher密码数组 用来存储密文
for (int i = 0; i <MingWen.length() ; i++) {
 int a= Math.floorMod((K1*MingWenNumber[i]+K2),36);
 cipherNum[i]=a;
 cipher[i]=form[a];
 //计算密文并存入数组中
}
System.out.println("加密结果是：");
System.out.println(cipher);
}

public static void decryption(char[] form,String Mingwen,int K2,int K3,int[] cipherNum){
char[] JieMI=new char[Mingwen.length()];
for (int i =0;i<Mingwen.length();i++){
 JieMI[i]=form[Math.floorMod(K3*(cipherNum[i]-K2),36)];
}
System.out.println("解密结果是：");
System.out.println(JieMI);
}
}

来源：https://blog.csdn.net/rtx_2080/article/details/86523035