java hash加密算法 java实现加密算法

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：

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：

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：