NFC Access Control needs help

Hi everyone, I am currently using Arduino Uno with NFC shield V2.0 from SeeedStudio. I am working to identify a card and allow it to access something. My progress at the moment is that I can work with Mifare Classic card and identify the card by its unique ID (UID) , but it seems that the UID of the card can be read by any readers (or I do not know how to prevent this stop happening), and since it depends on the UID, it can be cloned by UID writable card from China I intend to use Mifare Ultralight C instead since it supports 3DES for security. But I don't know what this 3DES can do to enhance the security after searching around. I think that it will protect not to authenticate the card to read info insinde (read UID) unless the card and the reader do not share the same "secret" keys. And I knew that for Mifare Ultralight, the shield will have to read differently with Mifare Classic. So do anyone have the library to work with Mifare Ultralight C for Arduino? Can anyone give me advice, what I should do next?

stop cross posting