Abstract: A system includes a data carrier drive apparatus and a data carrier apparatus. The data carrier apparatus includes a unit to output transmission data during a first state and adjustment data during a second state, and a current changer configured to change a current value of a current flowing from the data carrier drive apparatus to the data carrier apparatus according to data values of the transmission data and the adjustment data. The data carrier drive apparatus includes a detector to detect a detection value corresponding to the current value of the current, a determiner to determine the data value of the transmission data by comparing the detection value with a threshold value during the first state, and an updater to update the threshold value based on the detection value during the second state.

Abstract: A verification device is configured to supply operation power to a verification target device in order to communicate with the verification target device, and perform verification of the verification target device. The verification device includes: a detection unit configured to detect a value of a current that flows in the verification device due to the operation power being supplied to the verification target device; a determination unit configured to determine whether or not the value of the current is greater than a threshold value; and a verification unit configured to verify authenticity of the verification target device according to whether or not the value of the current is greater than the threshold value.

Abstract: An apparatus that operates with a detachable unit mounted therein, includes: a storage unit configured to store a public key; and a verification unit configured to verify data held by the mounted unit, based on the public key. The data includes attribute information indicating an attribute of the unit, and authentication information generated from target information including the attribute information with a secret key paired with the public key and from which the target information is restorable, and the verification unit is further configured to detect an anomaly in the attribute information or the authentication information included in the data, by determining whether the attribute information included in the target information restored from the authentication information using the public key matches the attribute information included in the data.

Abstract: A processing unit processes an input signal from an external apparatus and includes a first terminal to which a reference voltage is input from the external apparatus, a second terminal to which a first pulse signal having a first frequency is input from the external apparatus, and a control portion to process the input signal. A memory stores data to be transmitted to the external apparatus, and a clock generating unit generates a clock signal having a higher frequency than the first frequency of the first pulse signal. To transmit a data signal to the external apparatus from the processing unit, the control portion switches a load between the first terminal and the second terminal based on the data stored in the memory during a period in which a second pulse signal having a second frequency lower than the first frequency is input from the external apparatus.

Abstract: A system includes a data carrier drive apparatus and a data carrier apparatus. The data carrier apparatus includes: an unit configured to output transmission data during a first state and adjustment data during a second state; and a current changer configured to change a current value of a current flowing from the data carrier drive apparatus to the data carrier apparatus according to data values of the transmission data and the adjustment data. The data carrier drive apparatus includes: a detector configured to detect a detection value corresponding to the current value of the current; a determiner configured to determine the data value of the transmission data by comparing the detection value with a threshold value during the first state; and an updater configured to update the threshold value based on the detection value during the second state.

Abstract: An authentication method includes: at a first device, selecting an original key in which a first identifier has a first value and a second identifier has a second value from m original keys and generating an authentication key based on the selected original key and the authentication identifier; at a second device, selecting an authentication key generated from the original key in which the first identifier has the first value and the second identifier has the second value from n authentication keys, generating response data based on challenge data and the authentication key, and notifying the generated response data to the first device; at the first device, generating verification data based on the challenge data and the authentication key, and authenticating the authentication target device by comparing the verification data with the response data.

Abstract: A method of authenticating a target apparatus by an authentication apparatus that holds a first original key out of a plurality of original keys, and an identifier of the first original key, the target apparatus holding a first value and a plurality of derived keys generated by the plurality of original keys and the first value as inputs to a one-way function, the method includes: the target apparatus selecting a selected key from the plurality of derived keys based on the identifier and generating authentication data based on challenge data and a first generated key based on the selected key; and the authentication apparatus generating an authentication key by the first original key and the first value using the one-way function and generating comparison data based on the challenge data and a second generated key based on the authentication key.

Abstract: An authentication method includes: at a first device, selecting an original key in which a first identifier has a first value and a second identifier has a second value from m original keys and generating an authentication key based on the selected original key and the authentication identifier; at a second device, selecting an authentication key generated from the original key in which the first identifier has the first value and the second identifier has the second value from n authentication keys, generating response data based on challenge data and the authentication key, and notifying the generated response data to the first device; at the first device, generating verification data based on the challenge data and the authentication key, and authenticating the authentication target device by comparing the verification data with the response data.

Abstract: A data carrier apparatus includes a duty detector configured to determine a duty ratio of each pulse of a pulse signal that is received, a frequency detector configured to determine a period of each pulse of the pulse signal, and a demodulator configured to determine a value of data being carried by the pulse signal based on a determination result of the duty detector unit and a determination result of the frequency detector.

Abstract: A verification device is configured to supply operation power to a verification target device in order to communicate with the verification target device, and perform verification of the verification target device. The verification device includes: a detection unit configured to detect a value of a current that flows in the verification device due to the operation power being supplied to the verification target device; a determination unit configured to determine whether or not the value of the current is greater than a threshold value; and a verification unit configured to verify authenticity of the verification target device according to whether or not the value of the current is greater than the threshold value.

Abstract: An apparatus that operates with a detachable unit mounted therein, includes: a storage unit configured to store a public key; and a verification unit configured to verify data held by the mounted unit, based on the public key. The data includes attribute information indicating an attribute of the unit, and authentication information generated from target information including the attribute information with a secret key paired with the public key and from which the target information is restorable, and the verification unit is further configured to detect an anomaly in the attribute information or the authentication information included in the data, by determining whether the attribute information included in the target information restored from the authentication information using the public key matches the attribute information included in the data.

Abstract: A processing unit processes an input signal from an external apparatus and includes a first terminal to which a reference voltage is input from the external apparatus, a second terminal to which a first pulse signal having a first frequency is input from the external apparatus, and a control portion to process the input signal. A memory stores data to be transmitted to the external apparatus, and a clock generating unit generates a clock signal having a higher frequency than the first frequency of the first pulse signal. To transmit a data signal to the external apparatus from the processing unit, the control portion switches a load between the first terminal and the second terminal based on the data stored in the memory during a period in which a second pulse signal having a second frequency lower than the first frequency is input from the external apparatus.

Abstract: A verification device is configured to supply operation power to a verification target device in order to communicate with the verification target device, and perform verification of the verification target device. The verification device includes: a detection unit configured to detect a value of a current that flows in the verification device due to the operation power being supplied to the verification target device; a determination unit configured to determine whether or not the value of the current is greater than a threshold value; and a verification unit configured to verify authenticity of the verification target device according to whether or not the value of the current is greater than the threshold value.

Abstract: An apparatus that operates with a detachable unit mounted therein, includes: a storage unit configured to store a public key; and a verification unit configured to verify data held by the mounted unit, based on the public key. The data includes attribute information indicating an attribute of the unit, and authentication information generated from target information including the attribute information with a secret key paired with the public key and from which the target information is restorable, and the verification unit is further configured to detect an anomaly in the attribute information or the authentication information included in the data, by determining whether the attribute information included in the target information restored from the authentication information using the public key matches the attribute information included in the data.

Abstract: A communication apparatus includes a first terminal that receives a reference voltage, a second terminal that receives a pulse signal, and at least one processor to execute instructions. The instructions are executed to generate a clock signal that has a frequency higher than a frequency of the received pulse signal, count a number of pulses of the clock signal and determine a count value counted during a first cycle that is a cycle of the pulse signal to the second terminal, and, during a period of data transmission, increase or decrease an electric current that flows between the communication apparatus and the external apparatus according to a data value of data to be transmitted to the external apparatus. Data is transmitted to the external apparatus at least once during the first cycle, and data switch timing during the first cycle is based on the count value.

Abstract: A data carrier apparatus includes: a first determination unit configured to determine a duty ratio of each pulse of a pulse signal that is received; a second determination unit configured to determine a period of each pulse of the pulse signal; and a third determination unit configured to determine a value of data being carried by the pulse signal based on a determination result of the first determination unit and a determination result of the second determination unit.

Abstract: A method of authenticating a target apparatus by an authentication apparatus that holds a first original key out of a plurality of original keys, and an identifier of the first original key, the target apparatus holding a first value and a plurality of derived keys generated by the plurality of original keys and the first value as inputs to a one-way function, the method includes: the target apparatus selecting a selected key from the plurality of derived keys based on the identifier and generating authentication data based on challenge data and a first generated key based on the selected key; and the authentication apparatus generating an authentication key by the first original key and the first value using the one-way function and generating comparison data based on the challenge data and a second generated key based on the authentication key.

Abstract: A communication apparatus includes: a terminal to which a pulse signal is input from an external apparatus; an acquiring unit configured to acquire a count value during a first cycle that is a cycle of the pulse signal; and a transmitting unit configured to, during a period of data transmission, increase or decrease an electric current that flows between the communication apparatus and the external apparatus according to a data value of data to be transmitted. The transmitting unit is further configured to perform switching on the data to be transmitted at least once during the first cycle, and determine a data switch timing during the first cycle based on the count value.

Abstract: An apparatus that operates with a detachable unit mounted therein, includes: a storage unit configured to store a public key; and a verification unit configured to verify data held by the mounted unit, based on the public key. The data includes attribute information indicating an attribute of the unit, and authentication information generated from target information including the attribute information with a secret key paired with the public key and from which the target information is restorable, and the verification unit is further configured to detect an anomaly in the attribute information or the authentication information included in the data, by determining whether the attribute information included in the target information restored from the authentication information using the public key matches the attribute information included in the data.

Abstract: A verification device is configured to supply operation power to a verification target device in order to communicate with the verification target device, and perform verification of the verification target device. The verification device includes: a detection unit configured to detect a value of a current that flows in the verification device due to the operation power being supplied to the verification target device; a determination unit configured to determine whether or not the value of the current is greater than a threshold value; and a verification unit configured to verify authenticity of the verification target device according to whether or not the value of the current is greater than the threshold value.