用java实现4种加密解密算法（包括：换位加密解密、替换加密解密、位加密解密、一次一密）

痛定思痛。 2023-02-22 05:30 5阅读 0赞

#### 案例1： 换位加密解密算法 ####

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.*;
    
    public class demo { 
        static char[] jiami(char[] str, int n)                    //加密算法
        { 
            int i, j, k, d;
            int len;
            char[] temp, miwen, mtemp = { };
    
            len = str.length;                        //字符串长度
            if ((d = len % n) != 0) { 
                len = len + n - d;
            }
    
            if ((temp = new char[len + 1]) == null)    //申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            }
    
            if ((miwen = new char[len + 1]) == null)    //申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            } else { 
                mtemp = miwen;
            }
    
            System.arraycopy(str, 0, temp, 0, str.length);
            for (i = str.length; i < len; i++) { 
                temp[i] = 32;
            }
            temp[len] = '\0';
            i = 0;
            for (k = 0; k < n; k++)                    //转换，加密
            { 
                for (j = 0; j < len / n; j++) { 
                    mtemp[i] = temp[k + j * n];
                    i++;
                }
            }
            mtemp[i] = '\0';
            temp = null;
    
            return miwen;                        //返回密文
        }
    
        static char[] jiemi(char[] str, int n)                    //解密算法
        { 
            int i, j, k = 0, d;
            int len;
            char[] temp, mingwen, mtemp = { };
    
            len = str.length;
    
            if ((d = len % n) != 0) { 
                len = len - d;
            }
            n = len / n;
            if ((temp = new char[len + 1]) == null)    //申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            }
    
            if ((mingwen = new char[len + 1]) == null)    //申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            } else { 
                mtemp = mingwen;
            }
    
            System.arraycopy(str, 0, temp, 0, str.length);
            for (i = str.length; i < len; i++) { 
                temp[i] = 32;
            }
            temp[len] = '\0';
            i = 0;
            for (k = 0; k < n; k++)                    //恢复出明文
            { 
                for (j = 0; j < len / n; j++) { 
                    mtemp[i] = temp[k + j * n];
                    i++;
                }
            }
    
            while (mtemp[--i] == 32) ;
            i++;
            mtemp[i] = '\0';
            return mingwen;                        //返回明文
        }
    
    
        public static void main(String[] args) throws IOException { 
            int n, i;
            char[] srcstr = new char[100];
            char[] miwen;
            String go;
    
            System.out.print("换位加密解密算法演示！\n");
    
            do { 
                System.out.print("\n请先输入换位加密矩阵每行的字符数：");
                Scanner input = new Scanner(System.in);
                n = input.nextInt();                        //输入换位加密矩阵每行的字符数
    
                System.out.println("请输入明文：");
                //输入明文字符串
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
                String str = bufferedReader.readLine();
                srcstr = str.toCharArray();
    
                System.out.print("输入的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(srcstr[i]);
                }
    
                miwen = jiami(srcstr, n);                //加密
                System.out.print("\n加密后的密文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
                miwen = jiemi(miwen, n);                //解密
                System.out.print("\n解密出的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
    
                System.out.print("\n继续执行(y/n)?");
                go = input.next();
            } while (go.equalsIgnoreCase("y"));
            System.out.println("演示结束！");
        }
    }

#### 案例2： 替换加密解密算法 ####

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.Scanner;
    
    
    public class demo { 
        static char[] jiami(char[] str, int n)     //加密算法
        { 
            int i, len;
            char[] miwen;
    
            len = str.length;
            if ((miwen = new char[len + 1]) == null)    //申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            }
            for (i = 0; i < len; i++)                        //移位替换
            { 
                miwen[i] = (char) (str[i] + n);
            }
            miwen[len] = '\0';
            return miwen;
        }
    
        static char[] jiemi(char[] str, int n)        //解密算法
        { 
            int i, len;
            char[] mingwen;
    
            len = str.length;
            if ((mingwen = new char[len + 1]) == null)//申请内存
            { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            }
            for (i = 0; i < len; i++)                        //移位替换
            { 
                mingwen[i] = (char) (str[i] - n);
            }
            mingwen[len] = '\0';
            return mingwen;
        }
    
        public static void main(String[] args) throws IOException { 
            int i, n;
            char[] srcstr = new char[100];
            char[] miwen;
            String go;
    
            System.out.print("替换加密解密算法演示！\n");
    
            do { 
                System.out.print("\n请先输入替换加密解密算法中的密钥：");
                Scanner input = new Scanner(System.in);
                n = input.nextInt();                        //密钥
                System.out.print("请输入明文字符串：");
    
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
                String str = bufferedReader.readLine();
                srcstr = str.toCharArray();                //明文字符串
    
                System.out.print("输入的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(srcstr[i]);
                }
    
                miwen = jiami(srcstr, n);                //加密
                System.out.print("\n加密后的密文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
                miwen = jiemi(miwen, n);                //解密
                System.out.print("\n解密出的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
    
                System.out.print("\n继续执行(y/n)?");
                go = input.next();
            } while (go.equalsIgnoreCase("y"));
            System.out.println("演示结束！");
        }
    
    }

执行结果如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70]

#### 案例3：位加密解密算法 ####

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.Scanner;
    
    
    public class demo { 
        static char[] bitcode(char[] str, char n)                //位加密解密算法
        { 
            int i, len;
            char[] wen;
    
            len = str.length;
            if ((wen = new char[len + 1]) == null) { 
                System.out.print("申请内存失败!\n");
                System.exit(1);
            }
            for (i = 0; i < len; i++) { 
                wen[i] = (char) (str[i] ^ n);                    //异或运算
            }
            wen[len] = '\0';
            return wen;
        }
    
        public static void main(String[] args) throws IOException { 
            int i;
            char ch;
            char[] srcstr = new char[100];
            char[] miwen;
            String go;
    
            System.out.print("位加密解密算法演示！\n");
    
            do { 
                System.out.print("\n请先输入替换加密解密算法中的密钥：");
                Scanner input = new Scanner(System.in);
                ch = input.next().charAt(0);                        //密钥
                System.out.print("请输入明文字符串：");
    
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
                String str = bufferedReader.readLine();
                srcstr = str.toCharArray();                //明文字符串
    
                System.out.print("输入的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(srcstr[i]);
                }
    
                miwen = bitcode(srcstr, ch);                //加密
                System.out.print("\n加密后的密文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
                miwen = bitcode(miwen, ch);                //解密
                System.out.print("\n解密出的明文为：");
                for (i = 0; i < srcstr.length; i++) { 
                    System.out.print(miwen[i]);
                }
    
                System.out.print("\n继续执行(y/n)?");
                go = input.next();
            } while (go.equalsIgnoreCase("y"));
            System.out.println("演示结束！");
    
        }
    
    }

执行结果如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70 1]

#### 案例4： 一次一密加密算法 ####

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.Random;
    import java.util.Scanner;
    
    
    public class demo { 
        static int MAX = 100;
        static char[] key = new char[MAX];                            //用于保存密钥
        static int len;
    
        static char[] bitcode(char[] str)                    //一次一密加密算法
        { 
            int i;
            char[] wen;
    
            if ((wen = new char[len + 1]) == null) { 
                System.out.printf("申请内存失败!\n");
                System.exit(1);
            }
            for (i = 0; i < len; i++) { 
                wen[i] = (char) (str[i] ^ key[i]);                //异或运算
            }
            wen[len] = '\0';
            return wen;
        }
    
        public static void main(String[] args) throws IOException { 
            int i;
            char[] srcstr = new char[MAX];
            char[] miwen, mingwen;
            String go;
            Scanner input = new Scanner(System.in);
    // srand(time(NULL)); //随机种子
            System.out.printf("一次一密加密解密算法演示！\n");
    
            do { 
                System.out.printf("请输入明文字符串：");
    
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
                String str = bufferedReader.readLine();
    
                srcstr = str.toCharArray();
                //明文信息
                Random r = new Random();                    //随机种子
                len = srcstr.length;
                for (i = 0; i < len; i++) { 
                    key[i] = (char) (r.nextInt(10) + '0');            //产生密钥序列
                }
                System.out.printf("此次加密解密演示的密钥序列为：");
                for (i = 0; i < len; i++) { 
                    System.out.printf("%c", key[i]);
                }
    // System.out.printf("\n");
                miwen = bitcode(srcstr);                //加密
                System.out.printf("\n输入的明文为：");
                for (i = 0; i < srcstr.length; i++)
                    System.out.print(srcstr[i]);
                System.out.printf("\n加密后的密文为：");
                for (i = 0; i < miwen.length; i++)
                    System.out.print(miwen[i]);
                mingwen = bitcode(miwen);                //解密
                System.out.printf("\n解密出的明文为：");
                for (i = 0; i < mingwen.length; i++)
                    System.out.print(mingwen[i]);
    
                System.out.print("\n\n继续执行(y/n)?");
    
                go = input.next();
            } while (go.equalsIgnoreCase("y"));
            System.out.println("演示结束！");
    
    
        }
    
    }

执行结果如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70 2]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200702094620424.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200702094653357.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200702094723817.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N1aV95b25naHVh,size_16,color_FFFFFF,t_70