php加密算法之实现可逆加密算法和解密分享

function encrypt($data,$key)
{
$key=md5($key);
$x=0;
$len=strlen($data);
$l=strlen($key);
for ($i = 0; $i < $len; $i++)
{
if ($x == $l)
{
$x = 0;
}
$char .= $key{$x};
$x++;
}
for ($i = 0; $i < $len; $i++)
{
$str .= chr(ord($data{$i}) + (ord($char{$i})) % 256);
}
return base64_encode($str);
}

function decrypt($data,$key)
{
$key = md5($key);
$x = 0;
$data = base64_decode($data);
$len = strlen($data);
$l = strlen($key);
for ($i = 0; $i < $len; $i++)
{
if ($x == $l)
{
$x = 0;
}
$char .= substr($key,$x,1);
$x++;
}
for ($i = 0; $i < $len; $i++)
{
if (ord(substr($data,$i,1)) < ord(substr($char,1)))
{
$str .= chr((ord(substr($data,1)) + 256) - ord(substr($char,1)));
}
else
{
$str .= chr(ord(substr($data,1)) - ord(substr($char,1)));
}
}
return $str;
}

$data = 'PHP加密解密算法';// 被加密信息
$key = '123';// 密钥
$encrypt = encrypt($data,$key);
$decrypt = decrypt($encrypt,$key);
echo $encrypt,"n",$decrypt;

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PHP加密解密算法