Nonvolatile semiconductor memory device and memory system using the same

A nonvolatile semiconductor memory device comprising:

• a memory cell array which includes a first storage area and a second storage area, the first storage area storing secret key data and being inhibited from being written into and read from, and the second storage area being inhibited from being written into and permitted to be read from and storing encrypted key data and an expected value;
• an encryption arithmetic module which carries out an authentication operation based on the secret key data stored in the first storage area and message data externally supplied, the expected value stored in the second storage area being the result of carrying out the authentication operation on the secret key data based on a specific message;
• a storage module which stores a reference value;
• a detection module which detects the passing or failing of the authentication operation result from the encryption arithmetic module based on the reference value stored in the storage module and which outputs status data indicating the passing or failing;
• and
• a register which holds the status data output from the detection module.

A memory system comprising:

• a nonvolatile semiconductor memory device;
• and
• a host device,
• the nonvolatile semiconductor memory device comprising:
• a memory cell array which includes a first storage area and a second storage area, the first storage area storing secret key data and being inhibited from being written into and read from, and the second storage area being inhibited from being written into and permitted to be read from and storing encrypted key data and an expected value;
• and
• an encryption arithmetic module which carries out an authentication operation based on the secret key data stored in the first storage area and message data externally supplied, the expected value stored in the second storage area being the result of carrying out the authentication operation on the secret key data based on a specific message, and
• the host device reads an expected value stored in the second storage area when a defect has occurred in the nonvolatile semiconductor memory device, supplies the specific message to the encryption arithmetic module, and causes the encryption arithmetic module to compare the result of carrying out the authentication operation on the secret key data stored in the first storage area with the expected value based on the specific message.

A memory system comprising:

• a nonvolatile semiconductor memory device;
• and
• a host device,
• the nonvolatile semiconductor memory device comprising:
• a memory cell array which includes a first storage area and a second storage area, the first storage area storing secret key data and being inhibited from being written into and read from, and the second storage area being inhibited from being written into and permitted to be read from and storing encrypted key data and an expected value;
• an encryption arithmetic module which carries out an authentication operation based on the secret key data stored in the first storage area and message data externally supplied, the expected value stored in the second storage area being the result of carrying out the authentication operation on the secret key data based on a specific message;
• a storage module which stores a reference value;
• a detection module which detects the passing or failing of the authentication operation result from the encryption arithmetic module based on the reference value stored in the storage module and which outputs status data indicating the passing or failing;
• and
• a register which holds the status data output from the detection module, and
• the host device supplies the reference value to the nonvolatile semiconductor memory device when a defect has occurred in the nonvolatile semiconductor memory device, issues a first command to carry out the authentication operation, and issues a second command to read the status data held in the register.