多表代換密碼

一、實驗?zāi)康?、利用C語言編程實現(xiàn)多表代換加密與解密2、深入理解多表代換密碼原理二、實驗題目多表代換密碼要求：輸入密鑰字、明文，得密文，輸入密文，得明文明密文是26個小寫英文字母組成的字符串。三、算法與編碼算法：S1：輸入密鑰字、明文S2：將密鑰字與明文字符串?dāng)?shù)組轉(zhuǎn)換為一維整形數(shù)組，進(jìn)行加密運算S3：加密后再轉(zhuǎn)化為字符串?dāng)?shù)組S4：輸出密文S5：輸入密文S6：將密鑰字與明文字符串?dāng)?shù)組轉(zhuǎn)換為一維整形數(shù)組，進(jìn)行解密運算S7：解密后再轉(zhuǎn)化為字符串?dāng)?shù)組S8：輸出明文源代碼：#include<stdio.h>#include<string.h>charbiao[26]={'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'};//字母表intduiying(charc)//將字母逐個轉(zhuǎn)換成數(shù)字{ inti,d;for(i=0;i<26;i++)if(c==biao[i])d=i;returnd;}voidmain()//主函數(shù){ inti,j,k1,k2,length0,length1,length2; charkey[10],mingwen[100],miwen[100],miw[100],mingw[100]; printf("請輸入密鑰字:"); scanf("%s",key); printf("請輸入欲加密的明文:"); scanf("%s",mingwen); length0=strlen(key); length1=strlen(mingwen); for(k1=0;k1<length1+length0;k1=k1+length0)//加密過程 { for(i=k1;i<k1+length0;i++) { miwen[i]=biao[(duiying(mingwen[i])+duiying(key[i-k1]))%26]; } } printf("密文:%s\n",miwen); printf("請輸入欲解密的密文:"); scanf("%s",miw); length0=strlen(key); length2=strlen(miw); for(k2=0;k2<length2+length0;k2=k2+length0)//解密過程 { for(j=k2;j<k2+length0;j++) { mingw[j]=biao[(duiying(miw[j])-duiying(key[j-k2])+26)%26]; } } printf("明文:%s\n",mingw);}四、運行結(jié)果五、總結(jié)與心得1、利用字母表biao[26]和函數(shù)duiying()可以簡單地將字母與