trn1duq6vt4i8v66Ea9jo7qZ2X7JWmkf
3.進行解密，$key=”key:1111″,相同的密鑰串
<?php
header("content-type:text/html;charset=utf-8");
$key = "key:1111"; //密鑰
$cipher = MCRYPT_DES; //密碼類型
$modes = MCRYPT_MODE_ECB; //密碼模式
$iv = mcrypt_create_iv(mcrypt_get_iv_size($cipher,$modes),MCRYPT_RAND);//初始化向量
$str_encrypt="trn1duq6vt4i8v66Ea9jo7qZ2X7JWmkf";//這里的值是第2步中的$str_encrypt=base64_encode($str_encrypt);
$str_encrypt=base64_decode($str_encrypt);
echo "加密密文：".$str_encrypt." <p>";
$str_decrypt = mcrypt_decrypt($cipher,$key,$str_encrypt,$modes,$iv); //解密函數
echo "還原：".$str_decrypt;
運行結果：
加密密文：???v??”????c????~?Zi
還原：我是加密前的內容