一段php加密解密的代码

$key = "This is supposed to be a secret key !!!";  



function keyED($txt,$encrypt_key)  

{  

$encrypt_key = md5($encrypt_key);  

$ctr=0;  

$tmp = "";  

for ($i=0;$i
{  

if ($ctr==strlen($encrypt_key)) $ctr=0;  

$tmp.= substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1);  

$ctr++;  

}  

return $tmp;  

}  



function encrypt($txt,$key)  

{  

srand((double)microtime()*1000000);  

$encrypt_key = md5(rand(0,32000));  

$ctr=0;  

$tmp = "";  

for ($i=0;$i
{  

if ($ctr==strlen($encrypt_key)) $ctr=0;  

$tmp.= substr($encrypt_key,$ctr,1) .  

(substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1));  

$ctr++;  

}  

return keyED($tmp,$key);  

}  



function decrypt($txt,$key)  

{  

$txt = keyED($txt,$key);  

$tmp = "";  

for ($i=0;$i
{  

$md5 = substr($txt,$i,1);  

$i++;  

$tmp.= (substr($txt,$i,1) ^ $md5);  

}  

return $tmp;  

}  



$string = "Hello World !!!";  



// encrypt $string, and store it in $enc_text  

$enc_text = encrypt($string,$key);  



// decrypt the encrypted text $enc_text, and store it in $dec_text  

$dec_text = decrypt($enc_text,$key);  



print "Original text : $string
\n";  

print "Encrypted text : $enc_text
\n";  

print "Decrypted text : $dec_text
\n";  

?>  

分享：