AUTHENTICATION METHOD, AUTHENTICATION SYSTEM, AND AUTHENTICATION CHIP USING COMMON KEY CRYPTOGRAPHY
First Claim
1. An authentication method for authenticating, by a processor that controls a first device including a first authentication chip, a second device including a second authentication chip, the method comprising:
- generating a random number;
transmitting the random number to the first authentication chip and the second authentication chip;
receiving, from the first authentication chip, a first response value obtained by operating a first transform function, which is decided based on a value set in the first authentication chip, for an output value generated by operating an encryption function for performing encryption for an integer stored in the first authentication chip as a secret key and the random number;
receiving, from the second authentication chip, a second response value obtained by operating a second transform function, which is decided based on a value set in the second authentication chip, for the output value generated by operating the encryption function for performing encryption for an integer, which is stored in the second authentication chip as a secret key and is the same as the integer stored in the first authentication chip as the secret key, and the random number; and
authenticating the second device by making a comparison between a value obtained by operating, for the first response value, a third transform function, which is decided based on a number of a difference between the value set in the first authentication chip and the value set in the second authentication chip, and the second response value, or by making a comparison between a value obtained by operating the third transform function for the second response value and the first response value.
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Accused Products
Abstract
A method is disclosed for authenticating, by a processor that controls a parent device, a child device includes: authenticating the child device by making a comparison between a value obtained by operating, for a first response value, a third transform function, which is decided based on a number of a difference between the value set in an authentication chip of the parent device and the value set in an authentication chip of the child device, and the second response value, wherein a first and a second response values are obtained by operating a first and a second transform functions for output values generated by operating an encryption function for performing encryption for secret keys in authentication chips of the parent device and the child device, respectively.
17 Citations
14 Claims
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1. An authentication method for authenticating, by a processor that controls a first device including a first authentication chip, a second device including a second authentication chip, the method comprising:
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generating a random number; transmitting the random number to the first authentication chip and the second authentication chip; receiving, from the first authentication chip, a first response value obtained by operating a first transform function, which is decided based on a value set in the first authentication chip, for an output value generated by operating an encryption function for performing encryption for an integer stored in the first authentication chip as a secret key and the random number; receiving, from the second authentication chip, a second response value obtained by operating a second transform function, which is decided based on a value set in the second authentication chip, for the output value generated by operating the encryption function for performing encryption for an integer, which is stored in the second authentication chip as a secret key and is the same as the integer stored in the first authentication chip as the secret key, and the random number; and authenticating the second device by making a comparison between a value obtained by operating, for the first response value, a third transform function, which is decided based on a number of a difference between the value set in the first authentication chip and the value set in the second authentication chip, and the second response value, or by making a comparison between a value obtained by operating the third transform function for the second response value and the first response value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An authentication system where a first device authenticates a second device, comprising:
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a processor, included in the first device, configured to execute a process for generating a random number, for transmitting the random number to a first authentication chip included in the first device and a second authentication chip included in the second device, for respectively receiving a first response value and a second response value as responses to the random number from the first authentication chip and the second authentication chip, and for authenticating the second device by using the first response value and the second response value; the first authentication chip, connected to the processor, comprising first random number receiver configured to receive the random number, first storage configured to store an integer as a secret key, first encryption calculator configured to generate an output value by operating an encryption function for performing encryption for the integer stored as the secret key and the random number, and first response value generator configured to generate the first response value by operating a first transform function decided based on a first set value for the generated output value; and a second authentication chip, connected to at least the processor, comprising second random number receiver configured to receive the random number, second storage configured to store an integer as a secret key, second encryption calculator configured to generate an output value by operating an encryption function for performing encryption for the integer stored as the secret key and the random number, and second response value generator configured to generate the second response value by operating a second transform function decided based on a second set value for the output value, wherein the processor executes the process for authenticating the second device by making a comparison between a number, which is obtained by operating, for the first response value, a third transform function decided based on an absolute value of a difference between the first set value and the second set value, and the second response value, or by making a comparison between a number obtained by operating the third transform function for the second response value and the first response value.
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14. An authentication chip, comprising:
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a memory configured to store a secret key, which is an integer; receiver configured to receive the integer; response value generator configured to generate a response value obtained by operating a transform function for an output value generated by operating an encryption function for performing encryption for the integer and the secret key; and transmitter configured to transmit the response value.
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Specification