Authentication-gaining apparatus, authentication apparatus, authentication request transmitting method, authentication method, and program

An authentication apparatus comprising:

• a receiving unit comprising at least one camera configured to repeatedly read, during an authentication period, an authentication request containing encrypted information obtained through encryption using a cryptographic key and displayed by an authentication-gaining apparatus;
• a decrypting unit comprising at least one processor configured to decrypt the encrypted information, thereby acquiring decrypted information;
• an authentication unit comprising the at least one processor configured to judge whether or not the authentication-gaining apparatus is legitimate, using multiple authentication requests read during the authentication period and containing encrypted information that has been decrypted;
• and
• an output unit that outputs a judgment result by the authentication unit,
• wherein the authentication unit acquires multiple time differences of the multiple authentication requests read during the authentication period, and judges that the authentication-gaining apparatus is not legitimate in a case in which the acquired multiple time differences are not constant, each of the time differences being a difference between the time contained in decrypted information acquired from an authentication request and the reading time of the authentication request.

An authentication request displaying method comprising:

• for each of a plurality of authentication requests to be displayed during an authentication period:
• a step of generating mutually different respective unique information containing time;
• a step of encrypting the respective unique information using a cryptographic key, thereby generating corresponding encrypted information;
• and
• a step of displaying the authentication request containing the corresponding encrypted information so as to allow an authentication apparatus to read the authentication request, during the authentication period, wherein the authentication request is a display image,
• wherein the plurality of authentication requests displayed during the authentication period are used for making a single judgment of whether or not the authentication gaining apparatus is legitimate.

An authentication method comprising:

• a step of repeatedly reading an authentication request containing encrypted information obtained through encryption using a cryptographic key and displayed by an authentication-gaining apparatus, during an authentication period;
• a step of decrypting the encrypted information, thereby acquiring decrypted information;
• a step of judging whether or not the authentication-gaining apparatus is legitimate, using multiple authentication requests read during the authentication period and containing encrypted information that has been decrypted;
• and
• a step of outputting a judgment result in the step of judging whether or not the authentication-gaining apparatus is legitimate,
• wherein, in the step of judging whether or not the authentication-gaining apparatus is legitimate, multiple time differences of the multiple authentication requests read during the authentication period are acquired, and it is judged that the authentication-gaining apparatus is not legitimate in a case in which the acquired multiple time differences are not constant, each of the time differences being a difference between the time contained in decrypted information acquired from an authentication request and the reading time of the authentication request.

A non-transitory computer-readable storage medium storing a program for causing a computer to execute:

• for each of a plurality of authentication requests to be displayed during an authentication period:
• a step of generating mutually different respective unique information containing time;
• a step of encrypting the respective unique information using a cryptographic key, thereby generating corresponding encrypted information;
• and
• a step of displaying the authentication request containing the corresponding encrypted information so as to allow an authentication apparatus to read the authentication request, during the authentication period, wherein the authentication request is a display image,
• wherein the plurality of authentication requests displayed during the authentication period are used for making a single judgment of whether or not the authentication gaining apparatus is legitimate.

A non-transitory computer-readable storage medium storing a program for causing a computer to execute:

• a step of repeatedly reading an authentication request containing encrypted information obtained through encryption using a cryptographic key and displayed by an authentication-gaining apparatus, during an authentication period;
• a step of decrypting the encrypted information, thereby acquiring decrypted information;
• a step of judging whether or not the authentication-gaining apparatus is legitimate, using multiple authentication requests read during the authentication period and containing encrypted information that has been decrypted;
• and
• a step of outputting a judgment result in the step of judging whether or not the authentication-gaining apparatus is legitimate,
• wherein, in the step of judging whether or not the authentication-gaining apparatus is legitimate, multiple time differences of the multiple authentication requests read during the authentication period are acquired, and it is judged that the authentication-gaining apparatus is not legitimate in a case in which the acquired multiple time differences are not constant, each of the time differences being a difference between the time contained in decrypted information acquired from an authentication request and the reading time of the authentication request.