Access-control-purpose system, communication system, access control method, and program

1 . An access-control-purpose system that provides access information of first and second communication devices to the first and second communication devices that perform mutual authentication using ID-based encryption, the access-control-purpose system comprising:

a processor; and

a memory that includes instructions, which when executed, cause the processor to execute:

creating an access secret key by generating a hash value of a logical sum of a character string according to access information and a master secret key;

creating first authentication data by generating a hash value of a first authentication ID for the first communication device by using a first hash function, and creating second authentication data by generating a hash value of a second authentication ID for the second communication device by using a second hash function;

creating access confirmation data configured by a product of the access secret key and a generation source of a subgroup in a group on a first elliptic curve, and a product of the access secret key and a generation source of a subgroup in a group on a second elliptic curve; and

transmitting the first authentication data and the access confirmation data to the first communication device, and transmitting the second authentication data and the access confirmation data to the second communication device.

2 . The access-control-purpose system according to claim 1 , wherein the instructions, which when executed, cause the processor to execute:

creating the character string based on the access information.

3 . A communication system comprising:

the access-control-purpose system according to claim 1 ;

the first communication device; and

the second communication device.

4 . The communication system according to claim 3 , wherein the instructions, which when executed, cause the processor to execute:

creating, by the first communication device, a first secret key paired with a first authentication ID that is a public key on the basis of a first authentication secret key for the first communication device and the first authentication data;

performing, by the first communication device, mutual authentication with the second communication device by using the first authentication ID, the first secret key, and the access confirmation data; and

performing, by the first communication device, confirmation of an access permission with the second communication device using the first authentication ID, the first secret key, and the access confirmation data,

creating, by the second communication device, a second secret key paired with a second authentication ID that is a public key on the basis of a second authentication secret key for the second communication device and the second authentication data;

performing, by the second communication device, mutual authentication with the first communication device by using the second authentication ID, the second secret key, and the access confirmation data; and

performing, by the second communication device, confirmation of the access permission with the first communication device using the second authentication ID, the second secret key, and the access confirmation data.

5 . The communication system according to claim 4 , wherein the instructions, which when executed, cause the processor to execute:

processing by the first mutual authentication unit and the first access permission confirmation unit at the same timing, and

processing by the second mutual authentication unit and the second access permission confirmation unit at the same timing.

6 . An access control method executed by an access-control-purpose system that provides access information of first and second communication devices to the first and second communication devices that perform mutual authentication using ID-based encryption, the access control method comprising:

by the access-control-purpose system,

creating an access secret key by generating a hash value of a logical sum of a character string according to the access information and a master secret key;

creating first authentication data by generating a hash value of a first authentication ID for the first communication device using a first hash function, and creating second authentication data by generating a hash value of a second authentication ID for the second communication device using a second hash function;

creating access confirmation data configured by a product of the access secret key and a generation source of a subgroup in a group on a first elliptic curve, and a product of the access secret key and a generation source of a subgroup in a group on a second elliptic curve; and

transmitting the first authentication data and the access confirmation data to the first communication device, and transmitting the second authentication data and the access confirmation data to the second communication device.

7 . A non-transitory computer-readable recording medium having computer-readable instructions stored thereon, which when executed, cause a computer including a memory and a processor to execute the method according to claim 6 .