WO2011064833A1

WO2011064833A1 - Information processing apparatus, information processing method, and program

Info

Publication number: WO2011064833A1
Application number: PCT/JP2009/069776
Authority: WO
Inventors: 清彦鈴木; 輝顕伊東; 英之小黒
Original assignee: 三菱電機株式会社
Priority date: 2009-11-24
Filing date: 2009-11-24
Publication date: 2011-06-03
Also published as: TW201118640A; JPWO2011064833A1; JP5398845B2; TWI464616B

Abstract

In the authentication IC (21) for a master apparatus (2), a secret key is stored previously; in the authentication IC (31) for a slave apparatus (3), an IC-characteristic number and a secret key are stored previously and a HASH calculated value calculated with the secret key and the IC-characteristic number as arguments is stored. Whenever the master apparatus (2) detects a new slave apparatus (3) during operation, an arithmetic device (22) receives the IC-characteristic number from the authentication IC (31), the authentication IC (21) performs HASH calculation using the received IC-characteristic number and the stored secret key, and the arithmetic device (22) reads the HASH calculated value from the authentication IC (31) and compares the HASH calculated value calculated by the authentication IC (21) with the HASH calculated value read from the authentication IC (31), moving to the next-stage authentication operation when both of the values match.

Description

Information processing apparatus, information processing method, and program

The present invention relates to an inter-device authentication mechanism and an authentication method for counterfeit products, and more particularly to an authentication mechanism and an authentication method for authenticating a device with an inexpensive configuration and eliminating the risk of leakage of a secret key.

Damage caused by counterfeit products or pirated products continues to increase, and it is an urgent task for manufacturers to take measures against counterfeits.
Counterfeit products not only lead to the loss of potential market and brand image, but also increase the productivity of regular products due to increased troubles related to product liability.

In order to take measures against counterfeit products, it is necessary to provide some kind of authentication mechanism.
However, since the authentication mechanism prevents the use of a counterfeit product, the authentication mechanism is irrelevant to the original function of the device, which is a product, and the user has no direct merit.
On the other hand, in order to take countermeasures, costs such as parts procurement and development costs are necessary, and the costs required for countermeasures against these imitations are included in the cost of the product.
However, raising the price of the device for counterfeit countermeasures is a composition in which the user pays financially the functions unnecessary for the user, and usually cannot be understood by market users.
As a result, manufacturers recognize that a countermeasure against counterfeit goods is necessary, but often give up introduction due to cost constraints, and therefore it is important how it can be realized at low cost.

On the other hand, an authentication method using a challenge-response method is generally used technically. The challenge-response method will be briefly described below.
As an authentication technique using the challenge-response method described below, for example, there is a technique disclosed in Patent Document 1.

The operation of the challenge-response method is shown in FIG.
It is assumed that the master device authenticates the slave device, and it is assumed that the master device and the slave device share a secret key in advance.
In addition, both have the HASH calculation logic of the same algorithm.
In many cases, the SHA-1 algorithm is used for the HASH calculation logic, but the algorithm is arbitrary as long as the calculation logic has one-wayness.

Here, when the master device and the slave device have the same secret key and HASH calculation logic, if the HASH calculation logic is executed in both of them using the secret key and two values of an arbitrary value as arguments, the same HASH value is obtained. You should be able to get
The arbitrary value at this time serves as a challenge code for the master device to test whether the slave device is a partner that shares the same secret key.

Next, the operation of FIG. 14 will be described.
In order to authenticate the slave device, the master device generates a random number in the master device and passes it to the slave device (= challenge).
At the same time, the master device calculates the HASH value by inputting the generated random number and the secret key into the HASH calculation logic.
The slave device also performs the same calculation using the random number received from the master device, and transmits the HASH value to the master device (= response).
If the slave device is a regular slave device, the master device and the slave device should obtain the same HASH value because the master device shares the secret key.
The challenge-response method assumes that an attacker observes on the communication path.
Since only a random value and a HASH value based on the random number value can be exchanged on the communication path, if the generated random number changes every time, the value on the communication path always changes irregularly, so it is difficult to specify the secret key. is there.
Therefore, since a third party cannot know the secret key, if the slave device is authenticated by the challenge-response method before using the slave device, it can be known whether it is a genuine product.

Since the master device normally performs complicated processing, it has an arithmetic device such as a CPU (Central Processing Unit).
However, slave devices do not always have an arithmetic unit, and as an example, a memory device usually has only a memory circuit on a substrate.
Therefore, in recent years, when challenge-response authentication is performed between a master device and a slave device, the master device side is equipped with an arithmetic unit, and the slave side is attached with an authentication IC (Integrated Circuit) for authentication. Perform a series of challenge-response processes.

In recent years, with the widespread use of mobile phones, inferior illegal batteries for mobile phones have come out, and human life has been threatened by the firing of these illegal batteries.
Because of this social background, it is obliged to provide an authentication mechanism that can confirm whether or not a battery of a mobile phone is genuine.
Due to these social demands, authentication ICs for slave devices have become cheaper and more functional.

An example of a slave device IC is shown in Non-Patent Document 1.
The slave device IC generally has a HASH calculation logic, a secret key storage area that cannot be externally observed, and a nonvolatile storage area that can be externally observed. Sufficiently distributed.

While ICs for slave devices are becoming more sophisticated, authentication ICs for master devices are not generally distributed on the market, and creating them requires a great deal of cost and is not practical.
As a reason for this, it is conceivable that the master device usually has an arithmetic unit and functionally does not require an authentication IC.
Another reason is that the number of ICs for master devices is expected to be small compared to ICs for slave devices, resulting in higher unit prices and development and shipping by IC vendors for general use. It is possible that there is not.

JP 2009-086795 A

In a system consisting of one master device and multiple slave devices connected to it, taking counter measures against imitations means that imitation slave devices cannot be connected to genuine master devices, and that imitation master devices are authorized. To achieve that the slave device cannot be connected.

For this purpose, a challenge-response method can be used, and an inexpensive authentication IC for slave devices can be used on the slave device side.

On the other hand, in the conventional mounting, S / W (Software) mounting by an arithmetic device is the mainstream on the master device side.
However, in the conventional implementation, there is a case where memory data is observed from a debug I / O (Input Output) on the master device side and a secret key value is leaked.

As described above, countermeasures against counterfeit products are not only technical difficulties but also ease of introduction of costs, so it is desirable that countermeasures can be taken without introducing an authentication IC for the master device.

In view of these points, the main object of the present invention is to devise a device configuration and an authentication method for performing authentication processing with a simple configuration and preventing leakage of a key value.

An information processing apparatus according to the present invention includes:
A communication unit that receives an IC specific value unique to each IC and a matching value for matching from an IC (Integrated Circuit);
A secret key storage unit for storing the secret key;
A one-way calculation unit for performing one-way calculation on the secret key stored in the secret key storage unit and the IC eigenvalue received by the communication unit;
A determination unit that compares the collation value received by the communication unit with the calculation value calculated by the one-way calculation unit and determines whether the collation value and the calculation value match; It is characterized by.

According to the present invention, if the IC provided in the authentication object is a regular IC, the IC unique value and the collation value that matches the calculated value obtained from the one-way calculation for the secret key are stored. The validity of the authentication object can be determined by comparing the collation value received from the calculated value with the verification value.

FIG. 3 is a diagram illustrating a configuration example of an apparatus according to the first embodiment. FIG. 3 shows an internal configuration example of an authentication IC according to the first embodiment. FIG. 3 is a diagram illustrating an internal configuration example of the arithmetic device according to the first embodiment. The figure which shows the operation | movement corresponded to the authentication 1st step among the operation | movement which authenticates the slave apparatus which concerns on Embodiment 1. FIG. The figure which shows the operation | movement equivalent to the authentication 2nd step among the operation | movement which authenticates the slave apparatus which concerns on Embodiment 1. FIG. FIG. 3 shows an internal configuration example of an authentication IC according to the first embodiment. FIG. 6 is a diagram showing an operation of authenticating the validity of the authentication IC on the master device according to the first embodiment. FIG. 10 is a diagram illustrating an operation corresponding to the first authentication stage among the operations for authenticating the validity of the authentication IC on the master device according to the second embodiment. FIG. 10 is a diagram illustrating an operation corresponding to the second stage of authentication among operations for authenticating the validity of the authentication IC on the master device according to the second embodiment. FIG. 4 is a diagram illustrating an example of a device configuration according to a second embodiment. FIG. 6 is a diagram illustrating an internal configuration example of an authentication IC according to a second embodiment. FIG. 6 shows a configuration example of a master device according to a third embodiment. FIG. 4 is a diagram illustrating a hardware configuration example of a master device according to the first to third embodiments. The figure which shows a challenge-response system.

Embodiment 1 FIG.
FIG. 1 shows an example of a device configuration according to the present embodiment.
The authentication IC is mounted on the master device 2 and the slave device 3, and each is the same IC.
The master device 2 includes an authentication IC 21 and an arithmetic device 22, and the arithmetic device 22 includes an inward communication path 23 and an outward communication path 24.
An authentication IC 21 used by the master device is connected to the inward communication path 23.
The outward communication path 24 is a communication path for communicating with the slave device 3, and the authentication IC 31 is also connected to the slave device 3.
Although the authentication IC 21 and the authentication IC 31 are physically different, they are mechanically the same.
The mechanism of the authentication IC will be described later with reference to FIG.
The master device 2 is an example of an information processing apparatus, and the slave device 3 is an example of an authentication target.
The authentication IC 31 is an example of an authentication target IC, and the authentication IC 21 is an example of an auxiliary IC.

There is no need for one slave device 3, and there may be a plurality of slave devices 3 as long as they can be connected to the communication path 24.
In the present specification, description will be made assuming an example in which one slave device 3 is connected, but the operation is the same when a plurality of devices are connected.

The authentication IC 31 may exist on the communication path 24 or may be at the end of a gateway that straddles the communication path, and the position condition is that it can be controlled from the arithmetic device 22 in the master device 2.

The position of the authentication IC 21 does not need to be the inward communication path 23 and may be connected to the outward communication path 24 on the master device 2. The condition of the position is that it can be controlled from the arithmetic unit 22.

FIG. 2 shows a functional block diagram of the authentication IC according to the present embodiment.
The authentication IC 1 includes a data transmission / reception unit 11, a response code holding unit 12, an IC unique number storage unit 13, a HASH calculation logic unit 14, a secret key storage area 15, and a nonvolatile storage area 16. .
As shown in FIG. 6, both the authentication IC 21 and the authentication IC 31 assume the authentication IC 1 of FIG. 2 in terms of mechanism.
In the authentication IC 21, the HASH calculation logic unit 2114 functions as a one-way calculation unit, and the secret key storage area 2115 functions as a secret key storage unit.
Below, each component of authentication IC1 of FIG. 2 is demonstrated.

The data transmission / reception unit 11 interprets eight types of commands, and the issuer of the command is the arithmetic device 22 on the master device 2.
In this specification, commands are represented by COM1 to COM8.
The breakdown of COM1-8 is as follows.

COM1 is a command for the master device 2 to designate a communication partner.
In the COM1 command, the master device 2 outputs the IC unique number of the communication partner to the communication path, and recognizes that the authentication IC holding the same IC unique number is designated by itself.
The authentication IC designated by COM1 waits for one command for the next command, and when receiving this, performs processing according to the received command.
When this is finished, the authentication IC cancels the recognition designated by itself.
The master device 2 needs to specify the authentication IC again with COM1 before commanding another process.

If the unique number of the authentication IC is unknown, the authentication IC cannot be specified.
Therefore, a COM8 command is prepared, and all the authentication ICs existing on the communication path output their own unique numbers on the communication path.
The communication path is subjected to competition control in a physical layer such as a CSMA (Carrier Sense Multiple Access) system so that electric signals do not compete.
The master device 2 periodically outputs a COM8 command and confirms the presence of the authentication IC on the communication path.

COM2 is a command that receives a challenge code from the master device 2 and executes HASH calculation logic.
The calculated HASH value is stored in the response code holding unit 12.
There are two types of execution of the HASH calculation logic. The HASH calculation logic is executed with the key value and the value transmitted from the master side (= the challenge code in the challenge-response) as an argument, and the key value, the value transmitted from the master side and the nonvolatile storage. The HASH calculation logic may be executed using the value of the area 16 as an argument.
This distinction is as follows.

First, the master side outputs a COM2 command and then outputs a value to be transmitted to the slave side to the communication path 24.
When the HASH calculation is performed immediately, a predetermined code for executing the HASH calculation is output to the communication path 24.
Or when including the value of the non-volatile storage area 16, after outputting the transmission value to the slave side following the COM2 command, a predetermined code for prompting the use of the non-volatile storage area 16 is output on the communication path 24, Finally, a code for executing the HASH calculation is output to the communication path 24.

COM3 is a command for the master device 2 to read the HASH calculation result.
Upon receiving this command, the authentication IC outputs the value stored in the response code holding unit 12 on the communication path.
When the calculation is not completed, a special value indicating that the calculation is not completed, such as a value 0, is output in advance to notify the master device 2 that the calculation is not completed.

COM4 is a command for the master to store the secret key in the authentication IC.
Since the master device 2 outputs the secret key on the communication path after the command code of COM4, the authentication IC receives the value.
It should be noted that once the secret key is set, a mechanism that cannot be set again may be used.
Alternatively, the following mechanism may be used.
Before shipping, the secret key is set once in the authentication IC by the COM 4, and the value of the secret key is unconditionally adopted as the secret key.
After that, when the authentication IC already holds the secret key, the master device 2 outputs the secret key to the communication path after the COM4 command code, and then outputs the HASH value of the current secret key to the communication path.

COM5 is a command for the master device 2 to read an IC unique number from the IC unique number storage unit 13.
When the authentication IC receives this command, it outputs the IC unique number to the communication path.
COM8 is normally issued from the master, but COM5 is used to immediately confirm the IC unique number, and when the response of COM5 is not obtained, it means that the connection of the device having the authentication IC is released. .

COM 6 is a command used when the master device 2 transmits a value stored in the nonvolatile storage area 16.
After outputting the command code on the communication path, the master device outputs the storage destination address and the stored value, and further outputs the value of the HASH calculation result using the stored value and the secret key as arguments.
It is assumed that the amount of transmission is determined in advance, such as 1 byte.
When the authentication IC receives the command, it temporarily stores the subsequent value and performs HASH calculation together with the secret key.
Only when the HASH calculation result matches the HASH value output from the master device 2, the received value is stored in the designated address.

COM 7 is a command for the master device 2 to read a value stored in the nonvolatile storage area 16.
Following this command, the master device 2 outputs a read destination address on the communication path, and in response to this, the authentication IC outputs the value stored in the designated address in the nonvolatile storage area 16 on the communication path.
It is assumed that the amount of data to be read is determined in advance, such as 1 byte, as in the case of COM6.
This completes the description of the command.

The response code holding unit 12 is an area for temporarily storing the HASH calculation result in the authentication IC until the master device 2 reads the response code.
Once the value is read from the master device 2 via the data transmission / reception unit 11, the value is cleared to zero.
The reason for this is to prevent a third party other than the master device 2 from reading the value even if an attempt is made to read the value at an arbitrary timing.

The IC unique number storage unit 13 stores an IC unique number.
The IC unique number is a serial number assigned at the time of manufacturing the IC, and guarantees that the IC manufacturer is the only number in the world.

The HASH calculation logic unit 14 is a mechanism for performing HASH calculation such as challenge-response.
As long as the same function is implemented by those who perform authentication, the implemented HASH function is arbitrary.
That is, the authentication IC 21 and the authentication IC 31 in FIG. 1 are mechanically the authentication IC 1 and include the same HASH calculation logic unit.

The secret key storage area 15 is an area for storing a secret key.
It is necessary that the stored value cannot be read from the outside, and accordingly, a read request from the outside is not responded.
The secret key is stored in accordance with the operation described in the command COM4.

The non-volatile storage area 16 is an area used for storing information associated with the slave device 3, and a value that can be stored is preferably arbitrary.
One use example of the nonvolatile storage area 16 is as follows.
When the IC 1 is used for counterfeiting of printer toner, the printer is a master device and the toner is a slave device.
When used in this way, generally, the number of times the toner is used is stored in the nonvolatile storage area 16.

Next, an internal configuration example of the arithmetic unit 22 of the master device 2 is shown in FIG.

The control unit 221 controls the entire arithmetic device 22.
The communication unit 222 receives an IC unique number (authentication target IC unique value) stored in the authentication IC 31 in advance from the authentication IC 31 of the slave device 3 and a HASH value (authentication target IC) stored in the authentication IC 31 in advance. Receive the verification value).
In addition, the communication unit 222 issues the above-described COM1 to COM8.
The determination unit 223 compares the HASH value received by the communication unit 222 with the HASH value (calculated value) calculated by the HASH calculation logic unit 2114 of the authentication IC 21, and determines whether or not they match.
That is, the HASH calculation logic unit 2114 of the authentication IC 21 performs HASH calculation (one-way calculation) on the secret key stored in the secret key storage area 2115 and the IC unique number of the authentication IC 31 received by the communication unit 222. The HASH value is calculated, and the determination unit 223 collates the HASH value received from the authentication IC 31 with the HASH value calculated by the HASH calculation logic unit 2114 of the authentication IC 21.
res1 (224) is a register for accumulating the HASH value calculated by the HASH calculation logic unit 2114 of the authentication IC 21.
Res2 (225) is a register for accumulating the HASH value received from the authentication IC 31.

4 and 5 show an operation in which the master device 2 authenticates the slave device 3.
In the present embodiment, authentication of the master device 2 with respect to the slave device 3 is divided into two stages.
First, according to FIG. 4, it is confirmed that the authentication IC 31 is indeed an IC at the time of shipment of a genuine product, and then challenge-response authentication is performed according to FIG.
The operations of FIGS. 4 and 5 are performed once when the master device 2 detects a new slave device 3 on the communication path 24.

Prior to FIG. 4, the original master device 2 and the slave device 3 have a secret key stored at the time of shipment, and the non-volatile storage area 3116 existing in the authentication IC 31 of the slave device 3 includes the IC. Assume that a HASH value is stored with the unique number value and secret key as arguments.

For convenience, the operation of FIG. 4 is referred to as the first authentication stage, and the operation of FIG. 5 is referred to as the second authentication stage.
The first stage of authentication is processing unrelated to challenge-response authentication, and the second stage of authentication is challenge-response authentication itself.
The reason why the first stage of authentication is necessary will be described later.

The operation of the first authentication stage in FIG. 4 will be described.
4 and 5, the operation subject is the arithmetic device 22 on the master device, and the authentication IC 21 and the authentication IC 31 are driven according to various commands issued from the communication unit 222 of the arithmetic device 22.
In the master device 2 that has detected the new slave device, the communication unit 222 reads the IC unique number of the authentication IC 31 existing on the detected slave device 3, and uses this value as a challenge code to the authentication IC 21 in the master device 2. Send.
In the authentication IC 21, challenge-response processing is executed in the HASH calculation logic unit 2114 using the value of the IC unique number of the authentication IC 31 as a challenge code and the secret key as arguments, and a HASH calculation result is obtained.
In the arithmetic device 22, the communication unit 222 receives a response code (HASH calculated value) from the authentication IC 21.
Next, the communication unit 222 reads the HASH value stored in advance in the nonvolatile storage area 3116 in the authentication IC 31.
The HASH value in the nonvolatile storage area 3116 in the authentication IC 31 is a value stored in advance at the time of shipment. The determination unit 223 receives the response code (HASH calculated value) previously obtained from the authentication IC 21 and the authentication IC 31. Compare the HASH value.
If the two match, the first-stage authentication process is terminated and the second-stage authentication process is performed.
On the other hand, if they do not match, it means that a counterfeit has been detected and the slave is not used.

The operation will be described for the second stage of authentication in FIG.
As described above, the so-called challenge-response authentication is performed in the second authentication stage.
In the arithmetic device 22, the determination unit 223 generates a random value as a challenge code, and the communication unit 222 transmits the challenge code to both the authentication IC 21 on the master device 2 and the authentication IC 31 on the slave device 3.
Since the authentication IC 21 and the authentication IC 31 calculate the response codes of each other, the two response codes are acquired and matched, and if the values are equal, the newly connected slave device 3 can be determined to be a genuine product.
If the response codes of the two parties are different at the second stage of authentication, there is only a case where the secret keys do not match if there is no data destruction in the communication path 23 or the communication path 24.

In the first stage of authentication, it is confirmed whether the value of the secret key is correct and whether the authentication IC itself is a genuine product.
This is because device authentication is performed both physically and logically.
Challenge-response authentication is a method of authenticating the other party with the correctness of the secret key shared with each other, but is closed to logical calculations and has no relation to physical information.
Therefore, if an attacker has a genuine master device and a counterfeit slave device, the authentication IC on the legitimate master device is replaced with a commercial product authentication IC in its initial state, and a counterfeit slave device. Similarly, it is assumed that a commercial product authentication IC in the initial state is attached.
That is, with the configuration of FIG. 1, the authentication IC 21 and the authentication IC 31 are left in the initial state when a commercial product is purchased.
If only challenge-response authentication is performed under this condition, the authentication is closed with logical information, and the secret key matches with the initial value on both the master device side and the slave device side, and authentication is established.
Therefore, it is necessary to perform the first stage of authentication in order to make the authentication relevant to physical information and prevent the imitation product from being used by exchanging the authentication IC.

As described above, when the master device 2 detects the connection of the new slave device 3, the arithmetic device 22 performs the authentication processing of the slave device according to FIGS. 4 and 5.
In a series of operations, the authentication IC 21 on the master device 2 has an important role in terms of holding a secret key and executing a HASH operation.
Therefore, the master device 2 confirms the validity of its own authentication IC 21 when the power is turned on, and enters the normal operation state when the confirmation is obtained. It is necessary to operate so as to perform authentication processing according to 5.

Next, the operation for confirming the validity of the authentication IC 21 owned by the master device 2 will be described.

FIG. 7 is a diagram illustrating an authentication operation of the authentication IC 21 on the master device 2.
4 and 5 described above, that is, the operation in which the master device 2 authenticates the slave device 3 is performed by the authentication IC 31 on the slave device 3 on the premise that the authentication IC 21 on the master device 2 is correct and genuine. It is an operation to authenticate.
Compared with the operation, the authentication of the authentication IC 21 on the master device 2 does not have an entity that can guarantee that it is a genuine product at that time (that is, the authentication IC 21 in the master-slave authentication).
Therefore, the HASH value is stored in advance in the nonvolatile storage area 2116 of the authentication IC 21 at the time of shipment as in FIG.
Similarly to the first stage of authentication, this HASH value is a HASH value that uses the secret key and the value of the IC unique number of the authentication IC 21 as arguments, and is stored at the time of device shipment.

The authentication operation of the authentication IC 21 is generally the same as that in the first stage of authentication described in FIG. 4 except that the authentication target in the master device 2 is the authentication IC 21 on the master device 2.
The communication unit 222 of the arithmetic device 22 first receives an IC unique number value (auxiliary IC unique value) from the authentication IC 21 and inputs this value as a challenge code to the authentication IC 21 to obtain a response code (auxiliary IC calculated value).
On the other hand, the HASH value (auxiliary IC collation value) is stored in advance in the non-volatile storage area 2116 of the authentication IC 21, the communication unit 222 of the arithmetic device 22 reads out the HASH value, and the determination unit 223 previously obtained. Match the response code.
If it is the authentication IC 21 at the time of shipment, since the value of the IC unique number has not changed, the same HASH value should be obtained.
Therefore, if the values match, it shifts to the normal operation state, and if not, it means that the authentication IC has been exchanged and the authentication IC 21 is not authenticated.

If the attacker replaces the authentication IC 21 with a commercially available IC, the value in the nonvolatile storage area of the original authentication IC can be read, so the read value may be stored in the replacement authentication IC.
However, since the IC unique numbers are not the same, the HASH calculation result is different from the value stored in the nonvolatile storage area 2116.

In the authenticity authentication operation of the authentication IC 21 described in FIG. 7, the HASH value stored in the authentication IC 21 itself and the value calculated and output by the authentication IC 21 itself are used.
As long as an attacker who manufactures a counterfeit product uses the commercial authentication IC described in FIG. 2, it is possible to confirm the validity in FIG. 7, but instead of the IC, both the COM3 and the COM7 are used. If any device that returns the same value is attached, the authentication shown in FIG. 7 is established.
However, in this case, this time, it does not operate correctly at the time of authentication with the slave device 3.
In other words, since a legitimate slave device cannot be connected to the master device that has been imitated, countermeasures against the imitation product are taken as a result.

As described above, according to the present embodiment, it is possible to take counterfeit measures without placing a secret key in a place where it can be observed from the outside, with an inexpensive configuration using only a slave IC as an authentication IC.

Further, according to the present embodiment, even if the authentication ICs of both the master device and the slave device are replaced, it is possible to take countermeasures against counterfeit products, and therefore it is possible to prevent the authentication mechanism from being avoided by replacing parts. Become.

In addition, it is important that the authentication IC on the master device is properly attached and is an authentication IC attached at the time of shipment, that is, the validity of the authentication IC. According to this form, it is also possible to authenticate the validity of the authentication IC on the master device.

As described above, in the present embodiment, the mechanism for realizing counterfeit countermeasures that do not leak the secret key using only a relatively inexpensive authentication IC that does not have a special function has been described.
More specifically, in both the master device and the slave device, an authentication IC is provided at a position that can be controlled from the arithmetic device that manages the entire system on the master device. The authentication IC includes a data transmission / reception unit and a response code holding unit. The mechanism including the section, the IC unique number, the HASH calculation logic, the secret key storage area, and the non-volatile storage area has been described.
As a counterfeit countermeasure method, the HASH calculation result with the secret key and IC specific number as arguments is stored in advance in the nonvolatile storage area of the authentication IC, and the master device detects a new slave device during operation. Each time, the HASH calculation is recalculated by the authentication IC of the master device using the IC unique number and the secret key of the slave device, and the HASH value stored at the time of shipment is read out from the nonvolatile storage area provided in the authentication IC of the slave device, It has been described that the slave device is authenticated as a genuine product by matching the recalculated HASH value with the read HASH value.

Further, the counterfeit product countermeasure method further includes that the authentication IC on the master device is properly attached and is the authentication IC attached at the time of shipment, that is, the validity of the authentication IC, It was explained that it includes a method that makes it possible to authenticate.

The counterfeit countermeasure method allows counterfeit countermeasures even when the authentication ICs of both the master device and the slave device are replaced. Therefore, it is possible to prevent the authentication mechanism from being avoided by replacing parts. I explained that.

Embodiment 2. FIG.
When a unique number other than the IC unique number of the authentication IC 21 exists on the master device 2 and when two types of HASH values can be stored in the nonvolatile storage area 2116 in the authentication IC 21, It is possible to strengthen the procedure for authenticating other authentication ICs.
This process is shown in FIGS.
In this embodiment, since the process of authenticating the authenticity of the authentication IC 21 on the master device 2 is performed in two stages, FIG. 8 is called the first authentication stage and FIG. 9 is called the second authentication stage.
4 and 5, the terms “first authentication stage” and “second authentication stage” are used. However, FIGS. 4 and 5 show the authentication between the master device 2 and the slave device 3, and FIG. Since 9 is authentication of the authentication IC 21 on the master device 2, the meaning is different.
8 is the same processing as FIG. 7, and FIG. 9 is performed after that.
Note that the second authentication stage in FIG. 9 may be performed first, and then the first authentication stage in FIG. 8 may be performed.
The authentication IC 21 is not valid if it must be authenticated in both the first and second authentication stages, and if it is authenticated in one stage but not in the other stage.

Further, FIG. 10 shows a device configuration assumed in the present embodiment, and FIG. 11 shows a configuration of the authentication IC.
The configuration of the arithmetic unit 22 is the same as that in FIG.

The ASIC 25 described in FIG. 10 is not necessarily an ASIC (Application Specific Integrated Circuit), and may be a mechanism other than the authentication IC 21 having the unique number 251.
Further, the position of the ASIC 25 does not have to be on the communication path 24, and it is sufficient that the arithmetic device 22 can acquire the value of the unique number 251.
The unique number 251 is an example of a backup unique value, and the ASIC 25 is an example of a backup unique value storage unit.

FIG. 11 shows an authentication IC 21 similar to that in FIG. 2, and two areas # 1 and # 2 can be used as the non-volatile storage area 2116. The arithmetic unit 22 specifies # 1 by specifying the access destination address to the non-volatile storage area 2116. Alternatively, it is possible to distinguish access to # 2.

The HASH value is stored in advance in the nonvolatile storage area # 1 (21161) and the nonvolatile storage area # 2 (21162) in FIG. Both have different HASH values.
First, in the nonvolatile storage area # 1 (21161), as in FIG. 7, the result of the HASH calculation using the IC unique number of the authentication IC 21 and the secret key as arguments is stored.
Next, in the nonvolatile storage area # 2 (21162), the result (backup verification value) of the HASH calculation using the ASIC unique number 251 and the secret key as arguments is stored.

The description of FIG. 8 will be given.
The first stage of authentication is almost the same as that in FIG. 7 except that the nonvolatile storage area # 1 (21161) is read by the COM7.
However, the stored value is the same as the value stored in the non-volatile storage area of FIG.
If the HASH values match at the first authentication stage in FIG. 8, the process proceeds to the second authentication stage in FIG.

The description of FIG. 9 will be given.
In the first stage of authentication in FIG. 8, if the authentication IC 21 is the authentication IC described in FIG. 2, the authentication at the time of shipment is sufficient, but since it is self-authentication, the IC described in FIG. It may be a different mechanism.
Therefore, the HASH value is calculated using the unique number 251 of the ASIC 25 that is irrelevant to the authentication IC 21 itself.

In the computing device 22, the communication unit 222 inputs the unique number 251 of the ASIC 25 as a challenge code to the authentication IC 21, receives the unique number 251 and the HASH value (backup calculated value) for the secret key as a response, and receives the received response as the computing device. It is held in 22 registers.
Thereafter, the communication unit 222 reads the HASH value (backup comparison value) stored in advance in the nonvolatile storage area # 2 (21162), and the determination unit 223 determines the previous response (backup calculated value) and the nonvolatile storage area # 2. Compare with the HASH value (backup verification value) from (21162).
If the two match, the determination unit 223 determines that the authentication IC 21 is valid.

In the mechanism where the responses of COM3 and COM7 are simply the same, the attacker cannot deal with two-step authentication, and since information other than the authentication IC 21 on the master (unique number 251) is used, authentication is performed from another master device. It is impossible to peel off the IC and divert it by unauthorized repair.

As described above, according to the present embodiment, when a mechanism other than the authentication IC on the master device has some unique number, a method for authenticating the validity of the authentication IC on the master device is strengthened by using this mechanism. It becomes possible to do.

As described above, in the present embodiment, the method for authenticating the authenticity of the authentication IC of the master device has been described.
More specifically, the strength of authentication is enhanced when a unique number other than the IC unique number of the authentication IC exists on the master device and two types of HASH values can be stored in the nonvolatile storage area in the authentication IC. Explained how to make it possible.
The method authenticates the authenticity of the authentication IC on the master device in two stages, authentication with the IC unique number of the authentication IC and authentication with the unique number on the master device.

Embodiment 3 FIG.
In the first embodiment and the second embodiment described above, the example in which the authentication IC 21 is used has been described. In the present embodiment, a configuration in which the slave device is authenticated without using the authentication IC 21 will be described.

FIG. 12 shows a configuration example of the master device 2 according to the present embodiment.
The configuration of the slave device 3 is as shown in FIG. 1, and the configuration of the authentication IC 31 is also as shown in FIGS.

In FIG. 12, a control unit 221, a communication unit 222, a determination unit 223, res1 (224), and res2 (225) are the same as those shown in FIG.
The secret key storage unit 226 has the same function as the secret key storage area 2115 of the authentication IC 21.
That is, the secret key storage unit 226 stores a secret key that is secretly shared with the authentication IC 31 of the slave device 3.
The HASH calculation logic unit 227 has the same function as the HASH calculation logic unit 2114 of the authentication IC 21.
That is, the HASH calculation logic unit 227 performs HASH calculation using the same HASH function as the HASH calculation logic unit 3114 of the authentication IC 31.
The HASH calculation logic unit 227 is an example of a one-way calculation unit.

The operation of the computing device 22 in the present embodiment is the same as that of the first embodiment except that the operation of the authentication IC 21 of the first embodiment is performed in the computing device 22.

That is, in the first authentication stage, the communication unit 222 reads the IC unique number of the authentication IC 31 from the authentication IC 31 of the slave device 3, and transmits this value as a challenge code to the HASH calculation logic unit 227. The HASH calculation logic unit 227 Then, HASH calculation is performed using the value of the IC unique number of the authentication IC 31 and the secret key of the secret key storage unit 226 as arguments, and the HASH calculation value is obtained.
Next, the communication unit 222 reads the HASH value stored in advance in the nonvolatile storage area 3116 in the authentication IC 31.
Then, the determination unit 223 compares the response code (HASH calculation value) obtained by the HASH calculation logic unit 227 with the HASH value received from the authentication IC 31.
If the two match, the first-stage authentication process is terminated and the second-stage authentication process is performed.
On the other hand, if they do not match, it means that a counterfeit has been detected and the slave is not used.

In the second stage of authentication, the determination unit 223 generates a random value as a challenge code, and the communication unit 222 transmits the challenge code to both the HASH calculation logic unit 227 and the authentication IC 31 on the slave device 3.
Since the HASH calculation logic unit 227 and the authentication IC 31 calculate the response codes with each other, the response codes of both are acquired and matched, and if they are equal, it can be determined that the newly connected slave device 3 is a genuine product.

In the third embodiment, the authenticity of the slave device is determined by the S / W implementation in the arithmetic device without using the authentication IC 21 as in the first and second embodiments.
As described above, in the case of S / W implementation, there is a possibility that the memory data is observed from the debug I / O on the master device side and the secret key value may be leaked, but such secret key leakage is prevented. If a mechanism is provided, the legitimacy of the slave device can be determined without using the authentication IC 21 as in this embodiment.

As described above, in the present embodiment, the configuration in which the validity of the slave device 3 is determined without using the authentication IC 21 has been described.

Finally, a hardware configuration example of the master device 2 shown in the first to third embodiments will be described.
The master device 2 may be any device including the arithmetic unit 22 as shown in FIG. 1 and the like. In addition to the above-described printer, a computer such as a personal computer, a copy machine, a mobile phone, a car navigation device, various embedded devices, etc. Information equipment is assumed.
FIG. 13 is a diagram illustrating an example of hardware resources of the master device 2 described in the first to third embodiments.
Note that the configuration of FIG. 13 is merely an example of the hardware configuration of the master device 2, and the hardware configuration of the master device 2 is not limited to the configuration described in FIG. 13 and may be other configurations. .

In FIG. 13, the master device 2 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 corresponds to the arithmetic device 22.
The CPU 911 is connected to the authentication IC 906 via the bus 912. The authentication IC 906 corresponds to the authentication IC 21 in FIG.

Further, if the master device 2 is an information device, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, a display device 901, a keyboard 902, a mouse 903, an FDD 904 (Flexible Disk Drive). These are connected to a compact disk device 905 (CDD) and a magnetic disk device 920 to control these hardware devices.
The communication board 915 may support either wired communication or wireless communication. For example, the communication board 915 is connected to a LAN (local area network), the Internet, a WAN (wide area network), a SAN (storage area network), or the like. It doesn't matter.
The magnetic disk device 920 may store an operating system 921 (OS), a window system 922, a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911.

The program group 923 stores a program for executing the function described as “-unit” (excluding those included in the authentication IC) in the description of the first to third embodiments. The program is read and executed by the CPU 911.

In the description of the first to third embodiments, what is described as “to part” may be “to circuit”, “to device”, “to device”, and “to step” It may be “˜procedure” or “˜processing”.
That is, the information processing method according to the present invention can be realized by the steps, procedures, and processes shown in the flowcharts described in the first to third embodiments.

1 authentication IC, 2 master device, 3 slave device, 11 data transmission / reception unit, 12 response code holding unit, 13 IC unique number storage unit, 14 HASH calculation logic unit, 15 secret key storage region, 16 non-volatile storage region, 21 authentication IC , 22 arithmetic unit, 23 communication channel, 24 communication channel, 25 ASIC, 31 authentication IC, 221 control unit, 222 communication unit, 223 determination unit, 224 res1, 225 res2, 251 unique number, 2111 data transmission / reception unit, 2112 response code Holding part, 2113 IC unique number storage part, 2114 HASH calculation logic part, 2115 private key storage area, 2116 non-volatile storage area, 3111 data transmission / reception part, 3112 response code holding part, 3113 IC unique number storage part, 3114 H SH calculation logic, 3115 secret key storage area, 3116 the non-volatile memory area.

Claims

A communication unit that receives an IC specific value unique to each IC and a matching value for matching from an IC (Integrated Circuit);
A secret key storage unit for storing the secret key;
A one-way calculation unit for performing one-way calculation on the secret key stored in the secret key storage unit and the IC eigenvalue received by the communication unit;
A determination unit that compares the collation value received by the communication unit with the calculation value calculated by the one-way calculation unit and determines whether the collation value and the calculation value match; An information processing apparatus characterized by the above.
The communication unit is
From an authentication target IC provided in an authentication target other than the information processing apparatus, an IC specific value and a verification value stored in advance in the authentication target IC are received as an authentication target IC specific value and an authentication target IC verification value.
The one-way calculation unit
Perform one-way calculation on the authentication target IC eigenvalue received by the secret key and the communication unit stored in the secret key storage unit,
The determination unit
The authentication target IC verification value is compared with a value calculated by the one-way calculation unit, and the authentication target is not authenticated when the authentication target IC verification value does not match the calculated value. The information processing apparatus according to 1.
A value calculated by performing the same one-way calculation as the one-way calculation unit for the same secret key and the authentication target IC unique value as the secret key stored in the secret key storage unit is the authentication target IC verification. 3. The information processing apparatus according to claim 2, wherein, when received as a value, the determination unit determines that the authentication target IC collation value matches the calculated value. 4.
In the information processing apparatus, an IC including the secret key storage unit and the one-way calculation unit is provided as an auxiliary IC,
The communication unit is
The received authentication target IC specific value is transmitted to the one-way calculation unit of the auxiliary IC, and the calculated value is received from the one-way calculation unit of the auxiliary IC,
The determination unit
The information processing apparatus according to claim 2, wherein the authentication target IC collation value received by the communication unit is collated with the calculation value by the one-way calculation unit of the auxiliary IC.
The information processing device is provided with an auxiliary IC in which an IC eigenvalue and a collation value for collation are stored in advance,
The communication unit is
An IC eigenvalue of the auxiliary IC is received as an auxiliary IC eigenvalue from the auxiliary IC, and the received auxiliary IC eigenvalue is transmitted to the one-way calculation unit of the auxiliary IC, from the one-way calculation unit of the auxiliary IC A value calculated by performing one-way calculation on the auxiliary IC unique value and the secret key is received as an auxiliary IC calculated value, and further, a verification value of the auxiliary IC is received from the auxiliary IC as an auxiliary IC verification value. And
The determination unit
The auxiliary IC collation value received by the communication unit and the auxiliary IC calculated value are collated, and it is determined whether or not the auxiliary IC collation value matches the auxiliary IC calculated value. Item 5. The information processing apparatus according to Item 4.
The determination unit
The information processing apparatus according to claim 5, wherein the auxiliary IC is not authenticated when the auxiliary IC collation value does not match the auxiliary IC calculated value.
When the value calculated by performing the same one-way calculation as the one-way calculation unit for the secret key and the auxiliary IC eigenvalue is received as the auxiliary IC verification value, the determination unit receives the auxiliary IC verification value. 6. The information processing apparatus according to claim 5, wherein it is determined that a value matches the auxiliary IC calculated value.
The information processing apparatus is provided with an auxiliary IC in which two verification values are stored in advance as an auxiliary IC verification value and a backup verification value,
The information processing apparatus further includes:
A backup eigenvalue storage unit for storing eigenvalues other than the auxiliary IC eigenvalues as backup eigenvalues outside the auxiliary IC;
The communication unit is
The auxiliary IC eigenvalue is received from the auxiliary IC, the received auxiliary IC eigenvalue is transmitted to the one-way calculation unit of the auxiliary IC, and the auxiliary IC calculated value is transmitted from the one-way calculation unit of the auxiliary IC. Receiving the auxiliary IC collation value from the auxiliary IC, further receiving the backup eigenvalue from the backup eigenvalue storage unit, and transmitting the received backup eigenvalue to the one-way calculation unit of the auxiliary IC A value calculated by performing one-way calculation on the backup unique value and the secret key from the one-way calculation unit of the auxiliary IC as a backup calculation value, and receiving the backup verification value from the auxiliary IC. Receive
The determination unit
The auxiliary IC collation value received by the communication unit and the auxiliary IC calculated value are collated to determine whether or not the auxiliary IC collation value and the auxiliary IC calculated value match, and the communication unit 6. The information processing according to claim 5, wherein the backup collation value and the backup calculation value received by the collation are collated to determine whether or not the backup collation value and the backup calculation value match. apparatus.
The determination unit
The auxiliary IC is not authenticated when there is at least one of a mismatch between the auxiliary IC verification value and the auxiliary IC calculated value and a mismatch between the backup verification value and the backup calculated value. The information processing apparatus according to 8.
When the value calculated by performing the same one-way calculation as the one-way calculation unit for the secret key and the auxiliary IC eigenvalue is received as the auxiliary IC verification value, the determination unit receives the auxiliary IC verification value. It is determined that the value and the auxiliary IC calculated value match,
When the same one-way calculation as the one-way calculation unit is performed on the secret key and the backup unique value and the calculated value is received as the backup verification value, the determination unit receives the backup verification value and the backup verification value. The information processing apparatus according to claim 8, wherein it is determined that the backup calculation value matches.
The auxiliary IC is
The information processing apparatus according to claim 5, wherein the information processing apparatus is an IC having the same mechanism as the authentication target IC.
A device storing a secret key receives an IC specific value unique to each IC and a verification value for verification from an IC (Integrated Circuit),
The device performs a one-way calculation on the secret key and the received IC unique value,
The information processing method, wherein the device collates the received collation value with the calculated value calculated by the one-way calculation, and determines whether or not the collation value and the calculated value match.
To the device that stores the secret key,
A communication process for receiving an IC specific value unique to each IC and a matching value for matching from an IC (Integrated Circuit);
One-way calculation processing for performing one-way calculation on the secret key and the IC eigenvalue received by the communication processing;
The collation value received by the communication process is collated with the calculation value calculated by the one-way calculation process, and a determination process for determining whether or not the collation value and the calculation value match is executed. A program characterized by that.