Abstract: A memory controller performs a reliability test only on a memory array out of the memory array and a random number generator on receipt of a memory test command from a testing device while performing a reliability test only on the random number generator out of the memory array and the random number generator on receipt of a random number test command from the testing device.

Abstract: The communication device sends an authentication code (N) to a semiconductor memory to instruct the semiconductor memory to authenticate the communication device. The semiconductor memory authenticates the communication device based on the authentication code (N), and if the communication device is determined to be valid, sends an authentication code (N+1) to the communication device to instruct the communication device to authenticate the semiconductor memory in response to the authentication code (N). The communication device authenticates the semiconductor memory based on the authentication code (N+1).

Abstract: A noise generation module generates power consumption noise to conceal the power consumption characteristics of a cryptographic module. The cryptographic module performs first non-linear transformation on received data, and the noise generation module performs second non-linear transformation on received data during the operational period of the first non-linear transformation.

Abstract: An ECC circuit can operate in a plurality of error correction modes with different correcting capabilities for data stored in a memory. The ECC circuit calculates a syndrome with respect to information data in accordance with an error correction mode set by a control part and adds a syndrome of a fixed length in which dummy bits are added to the calculated syndrome, to the information data. When code data is read out, the ECC circuit performs a correction process on the code data by using the syndrome included in the code data.

Abstract: An object of the present invention is to provide a technique that makes it difficult to fabricate an illegal duplicate of a semiconductor storage apparatus. In a memory controller, an address acquisition unit acquires a latency-related designated address. The latency-related designated address is an address in the semiconductor memory storing data to be transmitted with the minimum latency upon reception of a read command, and is identical with an address held by a host. A pre-acquisition unit reads the data for the latency-related designated address from the semiconductor memory and stores it in the buffer. A comparator compares the address included in the read command to the latency-related designated address. Depending on the result of the comparison by the comparator, a transmission control unit transmits the data stored in the buffer to the host at the time point of completion of a minimum latency.

Abstract: A random number generating device includes an uncertain circuit which outputs uncertain data, and a cipher processing device. The cipher processing device encrypts input data using a cipher function of the cipher processing device, and generates a random number including higher uniformity than data outputted from said uncertain circuit using the cipher function of the cipher processing device and the data outputted from the uncertain circuit.

Abstract: A control circuit causes a first cryptographic module to perform a dummy operation in a command processing period and a data processing period in which a second cryptographic module performs a normal operation while the first cryptographic module does not perform a normal operation.

Abstract: A control circuit of a memory device feeds a first clock received from a transmission control circuit of a host device back to a reception control circuit of the host device as a second clock. The reception control circuit controls data reception from the memory device in synchronization with the fed-back second clock.

Abstract: A random number generating device includes an uncertain circuit which outputs uncertain data, and a cipher processing device. The cipher processing device encrypts input data using a cipher function of the cipher processing device, and generates a random number including higher uniformity than data outputted from said uncertain circuit using the cipher function of the cipher processing device and the data outputted from the uncertain circuit.

Abstract: A random number generation device includes a circuitry configured to output an output value of alternating 0 and 1 of two-valued logic, determine a sampling timing by generating data in which values change irregularly based on the output value, and generate a random number by sampling the output value at the sampling timing.

Abstract: A semiconductor memory includes a memory controller including a plurality of processing circuits. The plurality of processing units includes an encryption/decryption unit that encrypts and decrypts a signal transmitted to and from the memory controller. The encryption/decryption unit includes a self test unit that performs a reliability test of the encryption/decryption unit on receipt of a predetermined test command from a testing device.

Abstract: A memory controller performs a reliability test only on a memory array out of the memory array and a random number generator on receipt of a memory test command from a testing device while performing a reliability test only on the random number generator out of the memory array and the random number generator on receipt of a random number test command from the testing device.

Abstract: A technique for improving data security is provided. To be specific, in a memory system including an information processing apparatus and a semiconductor memory device, the semiconductor memory device has an interface section that transmits, to the information processing apparatus, data read out from a memory core according to a plurality of communication protocols having different signal transmission/reception methods. Based on a switch command inputted from the information processing apparatus, a communication protocol selection section inputs, to the interface section, a selection signal for selecting a particular communication protocol from the plurality of communication protocols.

Abstract: An ECC circuit can operate in a plurality of error correction modes with different correcting capabilities for data stored in a memory. The ECC circuit calculates a syndrome with respect to information data in accordance with an error correction mode set by a control part and adds a syndrome of a fixed length in which dummy bits are added to the calculated syndrome, to the information data. When code data is read out, the ECC circuit performs a correction process on the code data by using the syndrome included in the code data.

Abstract: The communication device sends an authentication code (N) to a semiconductor memory to instruct the semiconductor memory to authenticate the communication device. The semiconductor memory authenticates the communication device based on the authentication code (N), and if the communication device is determined to be valid, sends an authentication code (N+1) to the communication device to instruct the communication device to authenticate the semiconductor memory in response to the authentication code (N). The communication device authenticates the semiconductor memory based on the authentication code (N+1).

Abstract: An ECC circuit can operate in a plurality of error correction modes with different correcting capabilities for data stored in a memory. The ECC circuit calculates a syndrome with respect to information data in accordance with an error correction mode set by a control part and adds a syndrome of a fixed length in which dummy bits are added to the calculated syndrome, to the information data. When code data is read out, the ECC circuit performs a correction process on the code data by using the syndrome included in the code data.

Abstract: A random number generating device includes an uncertain circuit which outputs uncertain data, and a cipher processing device. The cipher processing device encrypts input data using a cipher function of the cipher processing device, and generates a random number including higher uniformity than data outputted from said uncertain circuit using the cipher function of the cipher processing device and the data outputted from the uncertain circuit.

Abstract: A technique allowing an improvement in the confidentiality of information stored in a memory device. A memory controller includes a key generation part that newly generates key information for use in encryption and decryption of information at every predetermined timing, and a data conversion circuit that encrypts information to be outputted to a memory device based on the information and decrypts encrypted information inputted from the memory device based on the key information. In the data conversion circuit, each time the key generation part generates new key information, key information is updated so as to set the new key information as the key information.

Abstract: An address comparator stores an address of data read out by a host system. Also, a buffer reads out the data from a memory and stores the data. If an address of data which is expected to be newly read out by the host system is included in addresses which have already been stored in the address comparator, the host system 1 newly reads out the data from the buffer, not from the memory. As a result, it is possible to eliminate or lessen the possibility of unintentional rewriting of data which is likely to be caused due to repeated readout of data.

Abstract: An address comparator stores an address of data read out by a host system. Also, a buffer reads out the data from a memory and stores the data. If an address of data which is expected to be newly read out by the host system is included in addresses which have already been stored in the address comparator, the host system 1 newly reads out the data from the buffer, not from the memory. As a result, it is possible to eliminate or lessen the possibility of unintentional rewriting of data which is likely to be caused due to repeated readout of data.