Access control apparatus, access control method, and program

An access control apparatus comprising:

• a secure module, a main processor, and a memory, wherein
• the memory stores target data to which access is requested,
• the secure module generates an individual key specific to the access control apparatus, wherein the individual key is newly generated each time the access control apparatus is started,
• the secure module generates, by using the individual key, integrity check value data that is based on verified digest value data and specific to the access control apparatus, wherein the integrity check value data is a truncated cipher-based message authentication code (CMAC) that is smaller in data size than the digest value data,
• the secure module accepts, from the main processor, an access request, based on a part of the integrity check value data read out from a kernel memory, to a block that is a part of the target data,
• the secure module calculates an integrity check value based on the block by using the individual key,
• the secure module compares the integrity check value indicated by the part of the integrity check value data corresponding to the block with the integrity check value calculated by the secure module, and
• the secure module writes the block to the memory in a case where the comparison succeeds.

An access control method comprising:

• generating an individual key specific to an access control apparatus that stores target data to which access is requested, wherein the individual key is newly generated each time the access control apparatus is started;
• generating, by using the individual key, integrity check value data that is based on verified digest value data and specific to the access control apparatus, and wherein the integrity check value data is a truncated cipher-based message authentication code (CMAC) that is smaller in data size than the digest value data;
• calculating, by using the individual key, an integrity check value based on a block that is a part of the target data to which access is requested;
• reading out, from a kernel memory, a part of the integrity check value data corresponding to the block that is part of the target data and issuing, to a secure module, an access request for the block;
• comparing the integrity check value indicated by the part of the integrity check value data corresponding to the block with the integrity check value calculated in the calculating;
• and
• writing the block to a memory in a case where the comparison succeeds.

A non-transitory computer-readable medium storing computer-readable instructions thereon which, when executed by a computer that stores target data to which access is requested, cause the computer to perform a method, the method comprising:

• generating an individual key specific to the computer, wherein the individual key is newly generated each time the computer is started;
• generating, by using the individual key, integrity check value data that is based on verified digest value data and specific to the computer, wherein the integrity check value data is a truncated cipher-based message authentication code (CMAC) that is smaller in data size than the digest value data;
• calculating, by using the individual key, an integrity check value based on a block that is a part of the target data to which access is requested;
• reading out, from a kernel memory, a part of the integrity check value data corresponding to the block that is part of the target data and issuing, to a secure module, an access request for the block;
• comparing the integrity check value indicated by the part of the integrity check value data corresponding to the block with the integrity check value calculated by the calculating;
• and
• writing the block to a memory in a case where the comparison succeeds.