利用openssl函数来加密数据，然后使用post方法将加密数据传递给服务器。
// 加密数据
$data = 'This is the data to be encrypted';
$key = 'This is the secret key';
$encrypted_data = openssl_encrypt($data, 'AES-128-ECB', $key);
// 使用POST方法传递加密数据
$url = 'http://example.com/receive_data.php';
$data = array('encrypted_data' => $encrypted_data);
$options = array(
'http' => array(
'header' => "Content-type: application/x-www-form-urlencoded\r\n",
'method' => 'POST',
'content' => http_build_query($data)
)
);
$context = stream_context_create($options);
$result = file_get_contents($url, false, $context);