古典密码加密解密之多表代换

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多表代换密码首先将明文M 分为由n 个字母组成的分组, , … ，对每个分组的加密为
≡ + ( ), = , , …
其中，（A,B）是密钥，A 是 × 的可逆矩阵，满足gcd(|A|,N)=1,( |A|是A 的行列式)， = (, , … ), =
(, , … ), = (, , … ),对密文的解密为
≡ −( − )( ), = , , …

java实现多表代换加密

import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Map.Entry;import java.util.Scanner;public class Mangboot {    private static Map<Integer, String> maps = new HashMap<Integer,String>();    public static int getKey(Map map,String value){        int key = 0;        Iterator it  = map.entrySet().iterator();        while(it.hasNext()){            Map.Entry entry = (Entry) it.next();            Object obj = entry.getValue();            if(obj!=null&&obj.equals(value)){                key=(int)entry.getKey();            }        }        return key;    }    /**     * 对字符和数字进行一一映射     */    public static void fuzhi(){        String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";        for(int i=0;i<str.length();i++){            maps.put(i, str.substring(i,i+1));        }            }    /**     * 加密的主要算法     * @param a  输入的A矩阵（密钥）     * @param d  需要加密的密文转换后的矩阵     * @param c  保存加密后的结果     * @param b  矩阵B（密钥）     * @param n  矩阵的维数     */    public static void addmatrixMultiply(int[][]a,int [][]d,int [][]c,int b[][],int n){        for(int i=0;i<n;i++)            for(int j = 0;j <1;j++){                int sum = a[i][0]*d[0][j];                for(int k = 1;k<n;k++)                    sum +=a[i][k]*d[k][j];                c[i][j] = sum+b[i][j];            }    }         public static void main(String[] args) {        fuzhi();        Scanner scanner = new Scanner(System.in);        System.out.println("请输入你要加密的明文:");        String str = scanner.nextLine();        System.out.println("请输入密钥");        System.out.println("请输入A矩阵的维数:");        int n = scanner.nextInt();        System.out.println("开始创建A矩阵:");        int a[][] = new int[n][n];        for(int i =0;i<n;i++){            for(int j= 0;j<n;j++){                a[i][j] = scanner.nextInt();            }        }        System.out.println("开始创建B矩阵:");        int b[][] = new int[n][1];        int c[][] = new int[n][1];        int d[][] = new int[n][1];        for(int j= 0;j<n;j++){            b[j][0] = scanner.nextInt();        }        System.out.println("获得的密文为:");        for(int i = 0;i<str.length()/n;i++){            String sub = str.substring(i*n, (i+1)*n);            for(int j= 0;j<n;j++){                d[j][0] = getKey(maps, sub.substring(j, j+1));            }            addmatrixMultiply(a, d, c,b, n);            for(int j= 0;j<n;j++){                System.out.print(maps.get(c[j][0]%26));            }            }            }}

java实现多表代换解密

import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Map.Entry;import java.util.Scanner;public class Mangbootjiemi {    private static Map<Integer, String> maps = new HashMap<Integer, String>();    public static int getKey(Map map, String value) {        int key = 0;        Iterator it = map.entrySet().iterator();        while (it.hasNext()) {            Map.Entry entry = (Entry) it.next();            Object obj = entry.getValue();            if (obj != null && obj.equals(value)) {                key = (int) entry.getKey();            }        }        return key;    }    public static void fuzhi() {        String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";        for (int i = 0; i < str.length(); i++) {            maps.put(i, str.substring(i, i + 1));        }    }    public static void addmatrixMultiply(int[][] a, int[][] d, int[][] c, int b[][], int n) {        for (int i = 0; i < n; i++)            for (int j = 0; j < 1; j++) {                int sum = a[i][0] * d[0][j];                for (int k = 1; k < n; k++)                    sum += a[i][k] * d[k][j];                c[i][j] = sum;            }    }    public static void main(String[] args) {        fuzhi();        Scanner scanner = new Scanner(System.in);        System.out.println("请输入你要解密的密文:");        String str = scanner.nextLine();        System.out.println("请输入密钥");        System.out.println("请输入A-1矩阵的维数:");        int n = scanner.nextInt();        System.out.println("开始创建A-1矩阵:");        int a[][] = new int[n][n];        for (int i = 0; i < n; i++) {            for (int j = 0; j < n; j++) {                a[i][j] = scanner.nextInt();            }        }        System.out.println("开始创建B矩阵:");        int b[][] = new int[n][1];        int c[][] = new int[n][1];        int d[][] = new int[n][1];        for (int j = 0; j < n; j++) {            b[j][0] = scanner.nextInt();        }        System.out.println("获得的明文为:");        for (int i = 0; i < str.length() / n; i++) {            String sub = str.substring(i * n, (i + 1) * n);            for (int j = 0; j < n; j++) {                d[j][0] = getKey(maps, sub.substring(j, j + 1)) - b[j][0];            }            addmatrixMultiply(a, d, c, b, n);            for (int j = 0; j < n; j++) {                            if (c[j][0]%26 < 0) {                    System.out.print(   maps.get(( c[j][0]% 26) + 26));                                    }else                                System.out.print(maps.get(c[j][0] % 26));            }        }    }}

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