Nintendo uses proprietary encryption to secure the data stored on the NFC chips within amiibo figures. Without the specific "retail" keys, software cannot access the information that identifies which character the amiibo represents or the game-specific data saved to it.
: Engage with communities that discuss technology in a respectful and legal manner. Many forums and websites are dedicated to understanding and developing with NFC and encryption technology within legal boundaries. amiibo retail encryption key pastebin