单表代换加密算法是比较经典的加密算法,事先准备好字母代换的相应对照表,即可实现加密解密,这里我们用JS进行实现。
明文字母与密文字母对应关系:
明文 | 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 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
密文 | W | J | A | N | D | Y | U | Q | I | B | C | E | F | G | H | K | L | M | O | P | R | S | T | V | X | Z |
JS实现算法:
//加密算法
function jiami(){
arr = nojiami.value.toLowerCase().split('');
console.log(arr);
var i = 0, j = 0;
while(i < arr.length){
for(j=0;j<25;j++){
if (arr[i] == a[j]){
arr[i] = b[j];
break;
}
}
i++;
}
yesjiami.value = arr.join('');
}
//解密算法
function jiemi(){
arr = yesjiami.value.toUpperCase().split('');
console.log(arr);
var i = 0, j = 0;
while(i < arr.length){
for(j=0;j<25;j++){
if (arr[i] == b[j]){
arr[i] = a[j];
break;
}
}
i++;
}
nojiami.value = arr.join('');
}
效果图:
完整代码:
<html>
<head>
<title>单表代换密码Demo</title>
</head>
<body>
<h1>单表代换密码</h1>
<br>
<h4>明文字母与密文字母对应关系:</h4>
<table border = 1>
<tr>
<th>明文</th>
<td>a</td>
<td>b</td>
<td>c</td>
<td>d</td>
<td>e</td>
<td>f</td>
<td>g</td>
<td>h</td>
<td>i</td>
<td>j</td>
<td>k</td>
<td>l</td>
<td>m</td>
<td>n</td>
<td>o</td>
<td>p</td>
<td>q</td>
<td>r</td>
<td>s</td>
<td>t</td>
<td>u</td>
<td>v</td>
<td>w</td>
<td>x</td>
<td>y</td>
<td>z</td>
</tr>
<tr>
<th>密文</th>
<td>W</td>
<td>J</td>
<td>A</td>
<td>N</td>
<td>D</td>
<td>Y</td>
<td>U</td>
<td>Q</td>
<td>I</td>
<td>B</td>
<td>C</td>
<td>E</td>
<td>F</td>
<td>G</td>
<td>H</td>
<td>K</td>
<td>L</td>
<td>M</td>
<td>O</td>
<td>P</td>
<td>R</td>
<td>S</td>
<td>T</td>
<td>V</td>
<td>X</td>
<td>Z</td>
</tr>
</table>
<hr>
<br><br>
<span>要加密的数据:</span>
<input type="text" id="nojiami" />
<br><br>
<button οnclick="jiami();">加密</button>
<button οnclick="jiemi();">解密</button>
<br><br>
<span>加密后的数据:</span>
<input type="text" id="yesjiami" />
</body>
<script>
/*
* 单表代换加密算法
*
*/
//密文对应关系
var a = ['a','b','c','d','e','f','g','h','i','g','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'];
var b = ['W','J','A','N','D','Y','U','Q','I','B','C','E','F','G','H','K','L','M','O','P','R','S','T','V','X','Z'];
var nojiami = document.getElementById("nojiami");
var yesjiami = document.getElementById("yesjiami");
//加密算法
function jiami(){
arr = nojiami.value.toLowerCase().split('');
console.log(arr);
var i = 0, j = 0;
while(i < arr.length){
for(j=0;j<25;j++){
if (arr[i] == a[j]){
arr[i] = b[j];
break;
}
}
i++;
}
yesjiami.value = arr.join('');
}
//解密算法
function jiemi(){
arr = yesjiami.value.toUpperCase().split('');
console.log(arr);
var i = 0, j = 0;
while(i < arr.length){
for(j=0;j<25;j++){
if (arr[i] == b[j]){
arr[i] = a[j];
break;
}
}
i++;
}
nojiami.value = arr.join('');
}
</script>
</html>