Abstract: An authentication apparatus includes a communication module, a storage module, a processing module and an authentication module. The communication module, based on a wireless communication protocol, establishes a communication link with an electronic apparatus. The storage module stores a plurality of encryption logics and a plurality of authentication logics corresponding to the plurality of encryption logics. The processing module chooses a first encryption logic among the plurality of encryption logics and transmits the first encryption logic to the electronic apparatus. The authentication module receives authentication data based on the first encryption logic from the electronic apparatus, retrieves a first authentication logic corresponding to the first encryption logic from the storage module, and authenticates the electronic apparatus according to the authentication data based on the first authentication logic.

Abstract: A decryption system is provided. The decryption system includes a first RFID tag, a second code providing apparatus and a decryption module. The first RFID tag is for storing an encrypted data generated by encrypting an original data according to a first code. The second code providing apparatus is for providing a second code. The decryption module includes an RFID reader and a computing unit. The RFID reader reads the encrypted data from the first RFID tag. The computing unit receives the second code from the second code providing apparatus without utilizing the Internet, and decrypts the encrypted data according to the second code to obtain the original data.