An authentication method performed between a memory including a memory area and a host, wherein the memory area at least includes: a first area which stores a first memory key (NKey) and unique secret identification information (SecretID), and is prohibited from being read from outside of the memory at least after shipping; a second area which stores index information and encrypted secret identification information (E-SecretID) generated by encrypting the secret identification information, and is required to be read-only from outside of the memory; and a third area which stores a family key block including a family key encrypted with a host identification key (IDKey), and is readable and writable from outside of the memory, and the host stores a first host key set (HKeyi, j (i=1,..., m)) and a number, includes a generator generating a random number, and communicates with the memory via a controller, the method comprising: generating, by the memory, a second key (HKey) based on AES with the first key (NKey) read from the first area of the memory area and the number received from the host; generating, by the memory, a memory session key (SKey) based on AES with the second key (HKey) and the random number received from the host; generating, by the memory, first authentication information (Oneway-ID) by calculating the secret identification information (SecretID) with the memory session key (SKey) in one-way function operation; transmitting, by the controller, the encrypted secret identification information (E-SecretID), the family key block, and the first authentication information (Oneway-ID) from the memory to the host via the controller; selecting, by the host, a host key (HKey) required to perform an authentication process from the host key set (HKeyi, j (i=1,..., m)) with the index information read from the second area of the memory area; generating, by the host, a host session key (SKey') based on AES with the host key (HKey') and the random number; generating, by the host, second authentication information (Oneway-ID') by calculating the secret identification information (SecretID) generated by decrypting the encrypted secret identification information (E-SecretID) with the host session key (SKey') in one-way function operation; and comparing, by the host, the first authentication information (Oneway-ID) with the second authentication information (Oneway-ID'). a first area which stores a first memory key (NKey) and unique secret identification information (SecretID), and is prohibited from being read from outside of the memory at least after shipping; a second area which stores index information and encrypted secret identification information (E-SecretID) generated by encrypting the secret identification information, and is required to be read-only from outside of the memory; and a third area which stores a family key block including a family key encrypted with a host identification key (IDKey), and is readable and writable from outside of the memory, and the host stores a first host key set (HKeyi, j (i=1,..., m)) and a number, includes a generator generating a random number, and communicates with the memory via a controller, generating, by the memory, a second key (HKey) based on AES with the first key (NKey) read from the first area of the memory area and the number received from the host; generating, by the memory, a memory session key (SKey) based on AES with the second key (HKey) and the random number received from the host; generating, by the memory, first authentication information (Oneway-ID) by calculating the secret identification information (SecretID) with the memory session key (SKey) in one-way function operation; transmitting, by the controller, the encrypted secret identification information (E-SecretID), the family key block, and the first authentication information (Oneway-ID) from the memory to the host via the controller; selecting, by the host, a host key (HKey) required to perform an authentication process from the host key set (HKeyi, j (i=1,..., m)) with the index information read from the second area of the memory area; generating, by the host, a host session key (SKey') based on AES with the host key (HKey') and the random number; generating, by the host, second authentication information (Oneway-ID') by calculating the secret identification information (SecretID) generated by decrypting the encrypted secret identification information (E-SecretID) with the host session key (SKey') in one-way function operation; and comparing, by the host, the first authentication information (Oneway-ID) with the second authentication information (Oneway-ID').