Integrated security device and signal processing method used for an integrated security device
An integrated security device, including: an encryption/decoding processing unit for executing processing necessary for authentication by using a logic circuit that forms an encryption/decoding function; a selector for selecting signals whose number corresponds to a specific number of lines from among signals from a plurality of intermediate nodes of the logic circuit in accordance with a selection signal; and a signal processing unit having a function of detecting a glitch caused by the signals corresponding to the specific number of lines, for implementing both a function of generating a physical random number and a function of generating a device identifier by a physical characteristic based on the glitch detected by switch-selecting the signals corresponding to the specific number of lines.
1. An integrated security device, comprising:
an encryption/decoding processing circuit configured to execute processing necessary for authentication by using a logic circuit that forms an encryption/decoding function;
a selection circuit configured to select signals whose number corresponds to a specific number of lines from among signals from a plurality of intermediate nodes of the logic circuit in accordance with a selection signal; and
a signal processing circuit configured to
supply the selection circuit with the selection signal for selectively executing a function of generating a physical random number or a function of generating a physical unclonable function (PUF) response,
detect a glitch caused by the signals corresponding to the specific number of lines selected by the selection circuit in accordance with the selection signal, and
execute the function of generating the physical random number and the function of generating the PUF response based on the glitch detected in accordance with the signals corresponding to the specific number of lines selected based on the selection signal.
2. The integrated security device according to claim 1 , wherein:
the encryption/decoding function is formed of iterative processing of sub-functions; and
the signal processing circuit is configured to acquire input information necessary for the function of generating the PUF response by selecting the signals corresponding to the specific number of lines from among signals updated by the iterative processing by supplying the selection circuit with the selection signal.
3. The integrated security device according to claim 1 , further comprising a key generator configured to protect a key necessary for the authentication by the PUF response generated by the signal processing circuit, and to generate challenge data necessary for the authentication by the generated physical random number,
wherein the encryption/decoding processing circuit is further configured to acquire the key and the challenge data from the key generator, and to process an authentication protocol by performing encryption/decoding processing necessary for the authentication.
4. The integrated security device according to claim 2 , further comprising a key generator configured to protect a key necessary for the authentication by the PUF response generated by the signal processing circuit, and to generate challenge data necessary for the authentication by the generated physical random number,
wherein the encryption/decoding processing circuit is further configured to acquire the key and the challenge data from the key generator, and to process an authentication protocol by performing encryption/decoding processing necessary for the authentication.
5. The integrated security device according to claim 1 , wherein:
the encryption/decoding processing circuit comprises a divided sub-function for executing processing in units divided by N, where N represents an integer equal to or greater than two, as one given sub-function that forms the encryption/decoding function;
the selection circuit comprises a switching circuit configured to feed back an output from an n-th division of the divided sub-function to an input to (n+1)th division of the divided sub-function, where n represents an integer equal to or greater than one and equal to or smaller than (N−1), in accordance with the selection signal; and
the signal processing circuit is configured to output the selection signal that corresponds to forming the switching circuit for feeding back when implementing the function of generating the physical random number, and to output the selection signal that corresponds to avoiding forming the switching circuit for feeding back when implementing the function of generating the PUF response.
6. The integrated security device according to claim 2 , wherein:
the encryption/decoding processing circuit comprises a divided sub-function for executing processing in units divided by N, where N represents an integer equal to or greater than two, as one given sub-function that forms the encryption/decoding function;
the selection circuit comprises a switching circuit configured to feed back an output from an n-th division of the divided sub-function to an input to (n+1)th division of the divided sub-function, where n represents an integer equal to or greater than one and equal to or smaller than (N−1), in accordance with the selection signal; and
the signal processing circuit is configured to output the selection signal that corresponds to forming the switching circuit for feeding back when implementing the function of generating the physical random number, and to output the selection signal that corresponds to avoiding forming the switching circuit for feeding back when implementing the function of generating the PUF response.
7. The integrated security device according to claim 3 , wherein:
the encryption/decoding processing circuit comprises a divided sub-function for executing processing in units divided by N, where N represents an integer equal to or greater than two, as one given sub-function that forms the encryption/decoding function;
the selection circuit comprises a switching circuit configured to feed back an output from an n-th division of the divided sub-function to an input to (n+1)th division of the divided sub-function, where n represents an integer equal to or greater than one and equal to or smaller than (N−1), in accordance with the selection signal; and
the signal processing circuit is configured to output the selection signal that corresponds to forming the switching circuit for feeding back when implementing the function of generating the physical random number, and to output the selection signal that corresponds to avoiding forming the switching circuit for feeding back when implementing the function of generating the PUF response.
8. The integrated security device according to claim 4 , wherein:
the encryption/decoding processing circuit comprises a divided sub-function for executing processing in units divided by N, where N represents an integer equal to or greater than two, as one given sub-function that forms the encryption/decoding function;
the selection circuit comprises a switching circuit configured to feed back an output from an n-th division of the divided sub-function to an input to (n+1)th division of the divided sub-function, where n represents an integer equal to or greater than one and equal to or smaller than (N−1), in accordance with the selection signal; and
the signal processing circuit is configured to output the selection signal that corresponds to forming the switching circuit for feeding back when implementing the function of generating the physical random number, and to output the selection signal that corresponds to avoiding forming the switching circuit for feeding back when implementing the function of generating the PUF response.
9. The integrated security device according to claim 1 , wherein the signal processing circuit is further configured to perform processing for generating the physical random number based on a transition state in repeatedly reading a signal having a predetermined bit transition probability a predetermined number of times via the selection circuit.
10. The integrated security device according to claim 2 , wherein the signal processing circuit is further configured to perform processing for generating the physical random number based on a transition state in repeatedly reading a signal having a predetermined bit transition probability a predetermined number of times via the selection circuit.
11. The integrated security device according to claim 3 , wherein the signal processing circuit is further configured to perform processing for generating the physical random number based on a transition state in repeatedly reading a signal having a predetermined bit transition probability a predetermined number of times via the selection circuit.
12. The integrated security device according to claim 4 , wherein the signal processing circuit is further configured to perform processing for generating the physical random number based on a transition state in repeatedly reading a signal having a predetermined bit transition probability a predetermined number of times via the selection circuit.
13. The integrated security device according to claim 1 , wherein:
the encryption/decoding function is formed of a plurality of logic stages, the encryption/decoding function comprising at least a first sub-function that forms a logic circuit on a first stage and a second sub-function that forms a logic circuit on a second stage; and
the signal processing circuit is configured to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the first sub-function when implementing the function of generating the PUF response, and to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the second sub-function when implementing the function of generating the physical random number.
14. The integrated security device according to claim 2 , wherein:
the encryption/decoding function is formed of a plurality of logic stages, the encryption/decoding function comprising at least a first sub-function that forms a logic circuit on a first stage and a second sub-function that forms a logic circuit on a second stage; and
the signal processing circuit is configured to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the first sub-function when implementing the function of generating the PUF response, and to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the second sub-function when implementing the function of generating the physical random number.
15. The integrated security device according to claim 3 , wherein:
the encryption/decoding function is formed of a plurality of logic stages, the encryption/decoding function comprising at least a first sub-function that forms a logic circuit on a first stage and a second sub-function that forms a logic circuit on a second stage; and
the signal processing circuit is configured to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the first sub-function when implementing the function of generating the PUF response, and to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the second sub-function when implementing the function of generating the physical random number.
16. The integrated security device according to claim 4 , wherein:
the encryption/decoding function is formed of a plurality of logic stages, the encryption/decoding function comprising at least a first sub-function that forms a logic circuit on a first stage and a second sub-function that forms a logic circuit on a second stage; and
the signal processing circuit is configured to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the first sub-function when implementing the function of generating the PUF response, and to supply the selection circuit with the selection signal that corresponds to selecting an output signal from the second sub-function when implementing the function of generating the physical random number.
17. A signal processing method for an integrated security device, comprising:
an encryption/decoding processing of executing processing necessary for authentication by using a logic circuit that forms an encryption/decoding function;
supplying a selection circuit with a selection signal for selectively executing a function of generating a physical random number or a function of generating a physical unclonable function (PUF) response;
selecting, by the selection circuit, signals whose number corresponds to a specific number of lines from among signals from a plurality of intermediate nodes of the logic circuit in accordance with the selection signal;
detecting a glitch caused by the selected signals corresponding to the specific number of lines selected by the selection circuit in accordance with the selection signal; and
executing the function of generating the physical random number and the function of generating the PUF response based on the glitch detected in accordance with the signals corresponding to the specific number of lines selected based on the selection signal.