JP7211472B2 - Data writing method - Google Patents

Description

The present invention relates to a data writing method.

An IC (Integrated Circuit) chip such as a SIM (Subscriber Identity Module or Subscriber Identification Module) stores secret information such as an encryption key and a PIN (Personal Identification Number), and uses the secret information to create a digital signature in the IC chip, There is a technique for performing arithmetic processing related to mutual authentication and the like. For example, Patent Literature 1 discloses an IC card having an IC chip mounted thereon that verifies a stored encryption key of a public key cryptosystem by itself.

An IC chip such as a SIM does not output confidential information such as an encryption key to the outside, and performs calculations using the confidential information within the chip. This guarantees the security of confidential information stored in the IC chip.

Japanese Unexamined Patent Application Publication No. 2007-13342

However, when confidential information is managed by a physical module such as an IC chip, the module must operate according to regulations such as ISO7816. , SoC (System on Chip), system LSI, and other general-purpose arithmetic modules. In addition, there is a risk that a bus for inputting data to a physical module such as an IC chip or outputting data from the module may be hacked, and data may be exploited or tampered with.

An object of one aspect of the present invention is to provide a control device or the like capable of safely storing secret information and executing processing using the secret information at high speed.

A control device according to one aspect comprises an input/output interface, a first execution region capable of inputting/outputting information via the input/output interface, and a virtual region to which access from the first execution region is restricted. and a second execution region that inputs and outputs information to and from the first execution region via a hypervisor, wherein the second execution region receives information via the input/output interface. input/output is disabled, predetermined confidential information is held, and processing using the confidential information is executed in response to a request from the first execution area.

In one aspect, secret information can be safely stored and processing using the secret information can be executed at high speed.

1 is a schematic diagram showing a configuration example of a chip issuing system; FIG. It is a block diagram which shows the structural example of a server. 3 is a block diagram showing a configuration example of a chip; FIG. It is explanatory drawing which shows an example of the record layout of product DB. FIG. 4 is an explanatory diagram showing an example of a record layout of a command table; FIG. 4 is an explanatory diagram showing an example of a record layout of a conversion table; 3 is a functional block diagram showing a configuration example of a chip; FIG. FIG. 4 is an explanatory diagram showing a process of writing data to a chip; FIG. 10 is an explanatory diagram for explaining data write processing after chip issuance; FIG. 10 is a flow chart showing an example of a data write process procedure in a chip issue stage; FIG. FIG. 10 is a flow chart showing an example of a processing procedure of data writing processing after issuing a chip; FIG.

Hereinafter, the present invention will be described in detail based on the drawings showing its embodiments.
(Embodiment)
FIG. 1 is a schematic diagram showing a configuration example of a chip issuing system. In the present embodiment, a data writing method for writing secret information to chips 2 mounted on various devices will be described. This system includes an information processing device 1 that instructs a chip (control device) 2 to write data.

The information processing device 1 is an information processing device capable of various types of information processing and transmission/reception of information, and is, for example, a server device, a personal computer, or the like. In the present embodiment, the information processing device 1 is assumed to be a server device, and will be replaced with the server 1 for the sake of brevity below. The server 1 instructs an issuing device (not shown) about data to be written in the chip 2 and causes each chip 2 to write the data. In addition, the server 1 is connected to a network N such as the Internet for communication, and upon receiving a request from a product manufacturer who manufactures a device (product) on which the chip 2 is mounted, or an end user who uses the device, the network N is opened. Remote control is performed to distribute data to the chip 2 via the chip 2 and write it.

The chip 2 is a control device mounted on various devices, and includes an arithmetic processing device such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read It is an integrated circuit that has a storage area such as only memory) on a single chip. Note that the chip 2 is not limited to a device called SoC, and may be any control device capable of executing general-purpose processing of the device, unlike a security chip such as SIM. Further, in this embodiment, the control device that holds confidential information is described as being a chip, but the control device does not have to be an integrated circuit, and may be a semiconductor circuit that is distributed within the device. .

Data such as an OS (operating system) and application programs are stored in a storage area of the chip 2, and the chip 2 operates according to the OS and application programs. In addition, predetermined confidential information is stored in the storage area of the chip 2 . The secret information includes, for example, unique information unique to each chip 2 (for example, the manufacturing number of the chip 2), key information used for cryptographic operations (for example, public key or secret key in public key cryptography, common key in common key cryptography, etc.). ), authentication information (for example, a PIN code) used for personal authentication and the like. Various confidential information is written in the chip 2 according to instructions from the server 1 .

Before describing the details of this system, an outline of the manufacturing process of the device illustrated in FIG. 1 will be described. In this embodiment, a device and a chip 2 mounted on the device are manufactured by a chip manufacturer who manufactures the chip 2, a chip issuer who writes data to the chip 2, and a chip 2 mounted on the device. The description will be made assuming that three parties, the product manufacturer that ships the product to the user, are in charge.

The chip manufacturer is a manufacturer of semiconductor components, manufactures the chip 2, and performs the minimum necessary initial settings. The initial settings include, for example, installation of a basic OS required for booting the chips 2, writing of unique information (for example, manufacturing number) that can uniquely identify each chip 2, and the like. The manufacturer writes the minimum required data in the chip 2 and ships it to the chip issuer.

The chip issuer is an issuer that receives orders from product makers, writes various data into the chip 2, and issues the chip. When receiving an order from a product maker, for example, an application program to be installed in the chip 2, secret information to be written in the chip 2, etc. are specified. For example, the server 1 stores various data specified by each product maker in a database, reads data to be written in each chip 2 from the database, and instructs writing. The chip 2 in which various data are written by the chip issuer is shipped to each product manufacturer.

Further, even after the chip 2 has been shipped (issued), the server 1 receives a request from the product maker or the end user and remotely writes data to the chip 2 via the network N. Details of the processing will be described later.

The product maker is a manufacturer that mounts the chip 2 delivered by the chip issuer in a device and ships the device to the user. Devices manufactured by product manufacturers can be various types of electronic equipment. For example, in addition to the smart phone shown in FIG. 1, an ECU (Electronic Control Unit) in a vehicle, home appliances, etc., it may be a personal computer, an infrastructure equipment, a wearable device, or the like. A device manufactured by a product maker may be an electronic device on which the chip 2 is mounted, and its content is not particularly limited.

For example, as shown in FIG. 1, each device may be connected to a network N and function as a thing related to the so-called IoT (Internet of Things).

FIG. 2 is a block diagram showing a configuration example of the server 1. As shown in FIG. The server 1 includes a control section 11 , a main storage section 12 , a communication section 13 and an auxiliary storage section 14 .
The control unit 11 has an arithmetic processing unit such as one or more CPU, MPU (Micro-Processing Unit), GPU (Graphics Processing Unit), etc., and reads and executes the program P stored in the auxiliary storage unit 14. , various information processing, control processing, and the like related to the server 1 are performed. The main storage unit 12 is a temporary storage area such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), flash memory, etc., and temporarily stores data necessary for the control unit 11 to perform arithmetic processing. Remember. The communication unit 13 includes a processing circuit and the like for performing processing related to communication, and transmits and receives information to and from other devices.

The auxiliary storage unit 14 is a large-capacity memory, a hard disk, or the like, and stores programs P and other data necessary for the control unit 11 to execute processing. The auxiliary storage unit 14 also stores a product DB 141 , a command table 142 and a conversion table 143 . The product DB 141 is a database that stores order data for each product (chip 2) ordered from a product maker. The command table 142 is a table storing commands used when data is transmitted and received between the server 1 and the chip 2 . The conversion table 143 is a table storing conversion rules for converting data to be transmitted and received when data is transmitted and received between the server 1 and the chip 2 .

Incidentally, the auxiliary storage unit 14 may be an external storage device connected to the server 1 . Moreover, the server 1 may be a multicomputer consisting of a plurality of computers, or may be a virtual machine virtually constructed by software.

Further, in the present embodiment, the server 1 is not limited to the configuration described above, and may include, for example, a reading unit for reading information stored in a portable storage medium.

FIG. 3 is a block diagram showing a configuration example of the chip 2. As shown in FIG. Chip 2 includes CPU 21 , RAM 22 , input/output I/F 23 and nonvolatile memory 24 .
The CPU 21 is an arithmetic processing device that executes various kinds of arithmetic processing, and reads various programs or data stored in the nonvolatile memory 24 to execute arithmetic processing. The RAM 22 is a temporary storage area, and temporarily stores data necessary for the CPU 21 to execute arithmetic processing. The input/output I/F 23 is an interface for inputting/outputting information with the outside of the chip 2 .

The nonvolatile memory 24 includes, for example, ROM, EEPROM (Electrically Erasable Programmable ROM), etc., and stores various data. Specifically, the nonvolatile memory 24 contains a rich OS 241, an application 242 operating under the environment of the rich OS 241, a secure OS 243, an application 244 operating under the environment of the secure OS 243, unique information 245, key information 246, authentication Information 247, command table 142, and conversion table 143 are stored.

The rich OS 241 , application 242 , secure OS 243 , and application 244 are programs that operate in separate virtual areas built inside the chip 2 . Specifically, the CPU 21 constructs within the chip 2 a rich area (first execution area) for executing normal execution processing and a secure area (second execution area) which is a virtual area that is more secure than the rich area. Then, various programs are executed in each virtual area. The CPU 21 executes a rich OS 241 and applications 242 in the rich area, and executes a secure OS 243 and applications 244 in the secure area. Details of each virtual area will be described later.

The unique information 245 is information unique to the chip 2, such as the manufacturing number of the chip 2, as described above. As will be described later, the server 1 rewrites the unique information 245 in response to a request from the product maker or the like, and writes the desired information as the unique information 245 into the nonvolatile memory 24 . The processing will be described later.

The key information 246 is a cryptographic key used for cryptographic calculations executed by the CPU 21, and is, for example, a key value such as a public key or secret key for public key cryptography, or a common key for common key cryptography.

The authentication information 247 is authentication data used for user authentication, for example, and is information personalized for each user. The authentication information 247 is, for example, a PIN code such as a password, biometric information for performing biometric authentication, and the like.

The command table 142 and the conversion table 143 are tables common to the command table 142 and the conversion table 143 held by the server 1 , and are tables used when data is transmitted and received with the server 1 .

FIG. 4 is an explanatory diagram showing an example of the record layout of the product DB 141. As shown in FIG. The product DB 141 includes a chip ID column, an orderer column, a product column, and a write data column. The chip ID column stores IDs for identifying each chip 2 . The order source column stores information on the product maker that ordered data writing to each chip 2 in association with the chip ID. The product column stores information on products (devices) on which the chip 2 is mounted, in association with the chip ID. The write data string stores data to be written to the chip 2 in association with the chip ID. Data to be written to the chip 2 are, for example, applications 242 and 244, unique information 245, key information 246, etc., as described above, but are not limited to these.

FIG. 5 is an explanatory diagram showing an example of the record layout of the command table 142. As shown in FIG. The command table 142 includes a command code string and a command content string. The command code string stores codes representing each command when data is transmitted and received between the server 1 and the chip 2 . The command content string stores the content of each command in association with the command code.

FIG. 6 is an explanatory diagram showing an example of the record layout of the conversion table 143. As shown in FIG. The conversion table 143 is a code table listing a plurality of codes. For example, as shown in FIG. 6, the conversion table 143 lists two-digit hexadecimal codes (character strings) from "00" to "FF". In the conversion table 143, odd-numbered row codes and even-numbered column codes correspond, and it is specified that the corresponding codes are mutually converted. For example, the code "00" in the first column of the first row corresponds to the code "5B" in the first column of the second row, and the code "00" is input to the conversion table 143. If so, it is converted to code "5B" and output.

FIG. 7 is a functional block diagram showing a configuration example of the chip 2. As shown in FIG. A rich area 201 and a secure area 202 constructed inside the chip 2 will be described with reference to FIG.
The chip 2 uses hardware resources such as the CPU 21 and the RAM 22 as a virtualization base, and constructs two virtual areas on the base. One virtual area is the rich area 201 and one virtual area is the secure area 202 .

The rich area 201 is a normal execution environment for executing basic and general-purpose processing of the device on which the chip 2 is mounted. is. For example, when the chip 2 is installed in a smart phone, the CPU 21 executes control processing related to calling, image display, etc. in the rich area 201 . A rich OS 241 and an application 242 are stored in the rich area 201, and the CPU 21 performs general-purpose processing by executing each program.

As shown in FIG. 7, the rich area 201 is configured to be able to input/output information to/from the outside through the input/output I/F 23 . For example, the CPU 21 acquires the content of an operation input by the user via the input/output I/F 23 and returns a response to the operation input (for example, a response to screen operation).

The secure area 202 is a more secure execution environment than the rich area 201 and is a virtual area to which access from the rich area 201 is restricted. For example, as shown in FIG. 7, direct access from the rich area 201 to the secure area 202 is prohibited. must be accessed through

In this embodiment, the chip 2 will be described as having two virtual areas, but the chip 2 may have a plurality of virtual areas, and may have three or more virtual areas.

Access to the secure area 202 from the rich area 201 is restricted, and executable processing is also restricted. Specifically, the CPU 21 executes security-important processing in the secure area 202 . For example, as shown in FIG. 7, the secure area 202 stores a secure OS 243, an application 244, etc., as well as unique information 245, key information 246, authentication information 247, etc., which are secret information. The CPU 21 performs processing using the confidential information in the secure area 202 . For example, the CPU 21 performs cryptographic computation using the key information 246 in the secure area 202 and outputs the encrypted data to the rich area 201 . Also, for example, the CPU 21 performs personal authentication using the authentication information 247 in the secure area 202 in response to a request from the rich area 201 .

A command table 142 and a conversion table 143 are stored in the secure area 202 . When the chip 2 transmits and receives data to and from the server 1, the CPU 21 uses each table in the secure area 202 to generate transmission data and analyze reception data.

In this embodiment, the secure area 202 is configured such that direct communication (input/output of information) with the outside of the chip 2 via the input/output I/F 23 is impossible. For example, as shown in FIG. 7, the hypervisor 203 is set to cut off the connection between the secure area 202 and the input/output I/F 23 and prohibit communication between the secure area 202 and the outside of the chip 2. . In order to input information to the secure area 202 from outside the chip 2 and obtain information from the secure area 202 , the rich area 201 and the hypervisor 203 must be passed through.

The secure area 202 executes security processing such as cryptographic operations only when a request is received from the rich area 201 via the hypervisor 203 . The secure area 202 outputs processing results of the security processing (for example, authentication results, encrypted data, etc.) to the rich area 201 and outputs them to the outside of the chip 2 via the rich area 201 .

As described above, the chip 2 has the rich area 201 and the secure area 202, and the secure area 202 holds confidential information. The secure area 202 is configured to be unable to communicate with the outside of the chip 2 via the input/output I/F 23, and only when a request is received from the rich area 201 via the hypervisor 203, various operations using secret information are performed. process. This allows the chip 2 to safely store confidential information.

Also, the chip 2 is not a physical module like an IC chip mounted on an IC card, but holds secret information in a secure software module within the chip and performs calculations. As a result, operations based on secret information and data exchange related to the operations can be executed at the bus level of the CPU, and the processing speed can be increased compared to the case where physical modules are implemented. Also, in a physical module such as an IC chip, there is a risk that the bus connected to the module will be hacked, data will be exploited, or malicious information will be input. However, when implemented as a software module as described above, resistance to hacking can be enhanced. This can improve security compared to implementing a physical module.

FIG. 8 is an explanatory diagram showing the process of writing data to the chip 2. As shown in FIG. FIG. 8 conceptually illustrates the process of writing various data such as the OS, applications, and secret information to the chip 2 .
FIG. 8 conceptually illustrates what data is written in a situation where there are chips 2 under each of the chip manufacturer, chip issuer, and product manufacturer.

First, the chip manufacturer writes the minimum required OS (rich OS 241 and secure OS 243) to operate the chip 2 and unique information 245 such as the manufacturing number of the chip 2. FIG.

Next, the chip issuer writes various data into the chip 2 according to the order received from the product maker so that the chip 2 performs customized operations according to the product. For example, the server 1 refers to the product DB 141 and sequentially writes data specified by each product maker to each chip 2 placed on the production line. For example, the server 1 writes the applications 242 and 244 and also writes the key information 246 used for cryptographic computation.

In this case, the server 1 rewrites the unique information 245 attached by the manufacturer of the chip 2 when requested by the product manufacturer.

The unique information 245 written by the manufacturer is, for example, the serial number of the chip 2, and is data added by the chip manufacturer so that each chip 2 can be uniquely identified. However, the data (number) is a value determined by the manufacturer of the chip 2, and is not necessarily a convenient value for product manufacturers or end users. For example, if the product on which the chip 2 is installed is assumed to be a portable medium such as a smartphone, the product functions as an employee ID card that authenticates based on the data stored in the chip 2, and is used like an IC card. There is In this case, a user (company or the like) must perform a two-step process of linking and managing the employee number and the production number, reading the production number from the chip 2, calling the employee number, and performing collation. This increases management costs.

Therefore, there is a need for some product manufacturers or end users to rewrite the unique information 245 itself to a desired value. Therefore, the server 1 accepts the value of the unique information 245 to be rewritten from the product maker (e.g. employee number) and rewrites the unique information 245 with the value. As a result, convenience for product manufacturers and end users can be enhanced.

In addition, the server 1 sets part or all of the confidential information to be rewrite-prohibited as necessary. For example, when the server 1 sets the unique information 245 to be rewrite-prohibited, the server 1 writes a flag to the effect that the rewriting of the unique information 245 is prohibited in the chip 2 and stores it in the secure area 202 . When the secure area 202 receives a request from the rich area 201 to rewrite the unique information 245, the secure area 202 refuses to rewrite. This prevents a malicious third party from rewriting confidential information.

It should be noted that which secret information is set to be rewrite-prohibited is a matter of design, and for example, the key information 246 may be set to be rewrite-prohibited. Further, the server 1 may receive designation from the product maker or the like as to which confidential information is set to be prohibited from being rewritten.

As described above, the chip 2 in which various data are written by the chip issuer is shipped to the product manufacturer. The product maker writes the authentication information into the chip 2 using a predetermined terminal device 4 having a reader/writer function. The authentication information written by the product maker is, for example, a password or the like initially set in the product. The chip 2 with the password initialized is incorporated into various products, and each product is shipped to the user. The user himself/herself changes the password, rewrites the authentication information, and uses it individually.

In this embodiment, the server 1 not only instructs the chip issuer to write data on the production line, but also communicates via the network N, receives a request from the product manufacturer, etc., and after issuing the chip 2 also writes data remotely.

Here, as an example, it is assumed that data is remotely written into the chip 2 issued by the chip issuer and delivered to the factory of the product maker. For example, some product manufacturers want to customize and update the applications 242 and 244 in the chip 2 for their company. In addition, although FIG. 8 shows only one product manufacturer for the sake of simplicity, a parts manufacturer that manufactures parts (for example, a vehicle ECU) on which the chip 2 is mounted and a whole product (for example, a vehicle) that is equipped with each device. There may be manufacturers that In this case, the maker who manufactures the whole product may wish to unify the unique information 245 of the chip 2 mounted on each part to the company's own identification number.

In such a case, the server 1 distributes the data requested by the product maker to the chip 2 and writes it into the nonvolatile memory 24 . For example, the terminal device 4 shown in FIG. 9 is connected to the network N, the chip 2 communicates with the server 1 via the terminal device 4, and acquires desired data.

However, if data writing to the chip 2 is allowed unconditionally, there is a risk that data may be illegally written by a third party. Therefore, in the present embodiment, data writing is permitted on condition that authentication between the server 1 and the chip 2 is successful.

Moreover, since data is distributed from the server 1 to the chip 2 via the network N, there is a risk that the data may be tapped and exploited by a third party on the communication path. Therefore, in this embodiment, the server 1 distributes the data after encrypting it, and the chip 2 restores the encrypted data to its original state, stores the restored data in the secure area 202, and writes the data. .

Specifically, the server 1 and the chip 2 exchange data using the command table 142 and the conversion table 143, and perform the authentication and encryption described above.

FIG. 9 is an explanatory diagram for explaining the data write processing after chip 2 is issued. Based on FIG. 9, data writing by the remote control described above will be described.
For example, an operator of a product maker operates the terminal device 4 and inputs predetermined information to the chip 2 to instruct the chip 2 to rewrite the confidential information. The information is input to secure area 202 via rich area 201 . In secure area 202 , chip 2 generates a transmission code shown in the upper right of FIG. 9 according to the input information and outputs it to rich area 201 .

The transmission code is a data code including a command code corresponding to the instruction content and a code designating data to be written (hereinafter referred to as "write data"). In FIG. 9, a code designating write data is concatenated with the command code indicated by "00" at the beginning. As noted above, command codes are defined in command table 142 . From the command table 142, the chip 2 reads a command code for requesting data distribution to the server 1 and generates a transmission code in FIG. The generated transmission code is output from the secure area 202 to the rich area 201 and transmitted to the server 1 .

Note that the write data may be confidential information such as the unique information 245 and the key information 246, or may be data that does not require confidentiality, such as the application 242 operating under the rich OS 241. FIG. Also, the write destination of the write data may be the secure area 202 or the rich area 201 .

The chip 2 converts the above command code according to the conversion table 143 in the secure area 202 . For example, as shown in FIG. 9, chip 2 converts command code "00" to "5B". Since the chip 2 uses the converted command code "5B" for authentication, it holds the command code.

When the transmission code is obtained from the chip 2, the server 1 determines that the chip 2 has issued a write data distribution request based on the command code "00" included in the transmission code. In this case, the server 1, like the chip 2, converts the command code "00" into "5B" according to the conversion table 143. FIG.

The server 1 generates a transmission code including the converted command code “5B” and the write data requested by the chip 2 . In this case, the server 1 converts the write data based on the conversion table 143 and uses the converted data as the transmission code. For example, when receiving a distribution request for the unique information 245 from the chip 2 , the server 1 converts the specified unique information 245 according to the conversion table 143 to generate a data code. As a result, the data to be written in the chip 2 is encrypted, and it is possible to deal with the case where the data is tapped and exploited on the communication channel by a third party. The server 1 transmits the generated transmission code to the chip 2 .

From the server 1, the chip 2 acquires the transmission code including the converted command code and the converted write data. A transmission code obtained from the server 1 is input to the secure area 202 via the rich area 201 .

In the secure area 202, the chip 2 executes authentication processing for authenticating the legitimacy of the server 1, which is the transmission source (input source) of the transmission code, based on the command code included in the transmission code. Specifically, the chip 2 collates the command code "5B" converted by itself with the command code "5B" converted by the server 1, and determines whether the two match. In this way, the server 1 and the chip 2 share the command table 142 and the conversion table 143, and by collating the data obtained by converting the same command code according to the conversion table 143, authentication of the transmission source of the write data is performed. I do. When the command code converted by the chip 2 and the command code converted by the server 1 do not match, the chip 2 determines that the authentication has failed and discards the data delivered from the server 1. - 特許庁

If it is determined that the command codes match, the chip 2 determines that the authentication has succeeded. In this case, the chip 2 converts the write data included in the transmission code according to the conversion table 143 to restore the original data. The chip 2 writes data by storing the restored data in the rich area 201 or the secure area 202 .

As described above, the server 1 remotely writes data to the chip 2 . In this case, the chip 2 performs authentication in the secure area 202 using data such as the command table 142 and the conversion table 143 written in the secure area 202 at the issuing stage. As a result, data can be safely written even remotely.

In the above description, the command code defined in the command table 142 is used for authentication, but authentication may be performed by means of collation of unique information 245, key exchange based on key information 246, or the like. In other words, the chip 2 only needs to be able to authenticate the validity of the sender of the write data using the secret information held in the secure area 202, and the secret information to be used is not limited to the command code.

Also, in the above description, the server 1 distributes the write data to the chip 2 and writes the data remotely, but the writing of the data may be performed locally. For example, the terminal device 4 may read data corresponding to the above transmission code from a portable storage medium and input it to the chip 2 . That is, the chip 2 only needs to be able to authenticate the validity of the input source of the write data, and may acquire the write data without going through a network N such as the Internet.

Also, for convenience of explanation, the case where the write data is distributed to the chip 2 in the factory of the product maker has been described above, but for example, the write data is distributed to the device in use by the end user and authenticated by the chip 2. to write data. As a result, for example, the expired rich OS 241, application 242, key information 246, etc. can be updated. In this manner, various modifications are conceivable in this embodiment.

FIG. 10 is a flow chart showing an example of the procedure of data write processing at the chip 2 issue stage. Based on FIG. 10, the data write processing in the manufacturing line of the chip issuer will be described.
The control unit 11 of the server 1 reads from the product DB 141 various data designated by the product maker to be written in the chip 2 (step S11). The data to be written to the chip 2 are, for example, applications 242 and 244 operating in the rich area 201 and the secure area 202 respectively, secret information to be written to the secure area 202, and the like. The confidential information is data used in the processing executed in the secure area 202 by the CPU 21 of the chip 2, such as the key information 246 used for cryptographic computation. In addition, the confidential information written in the chip 2 includes rewritten data of the unique information 245 written by the manufacturer of the chip 2 when requested by the product manufacturer.

The control unit 11 instructs to write the data read in step S11 to the chip 2 (step S12). For example, the control unit 11 transmits data such as the applications 242 and 244 and the key information 246 to the issuing device that writes data to the nonvolatile memory 24 of the chip 2, and requests that the data be written. The CPU 21 also writes a command table 142 and a conversion table 143 for remotely writing data to the chip 2 .

Further, the control unit 11 instructs to rewrite the secret information written in the chip 2 (step S13). For example, the control unit 11 instructs the chip 2 to rewrite the specific information 245 as described above.

The control unit 11 sets the chip 2 to prohibit part or all of the confidential information written in steps S12 and S13 from being rewritten (step S14). For example, the control unit 11 writes a flag to the nonvolatile memory 24 to prohibit the rewriting of any confidential information, and causes the secure area 202 to hold the flag. The control unit 11 ends the series of processes.

FIG. 11 is a flow chart showing an example of the procedure of data write processing after chip 2 is issued. Based on FIG. 11, the details of the process of remotely writing data to the chip 2 will be described.
For example, the chip 2 is connected to a predetermined terminal device 4 capable of communicating with the server 1 via the network N, and communicates with the server 1 via the terminal device 4 . The CPU 21 of the chip 2 requests the server 1 to distribute the write data (step S31). For example, in the secure area 202, the CPU 21 generates a transmission code including a command code defined by the command table 142 and a data code specifying data to be written. CPU 21 inputs the generated transmission code from secure area 202 to rich area 201 and transmits it to server 1 via network N. FIG. In addition, in the secure area 202, the CPU 21 converts the command code included in the transmission code using the conversion table 143 and stores it (step S32).

When a transmission code is obtained from the chip 2 and a request for distribution of write data is received, the control unit 11 of the server 1 refers to the transmission code received from the chip 2 and stores the write data requested by the chip 2 in the product DB 141. (step S33). For example, the control unit 11 determines that there is a distribution request based on the command code included in the transmission code, and determines the write data specified by the chip 2 from the code also included in the transmission code. The control unit 11 reads the write data from the product DB 141 .

The control unit 11 converts the command code acquired from the chip 2 and the write data read from the product DB 141 according to the conversion table 143 (step S34). The conversion table 143 is a table that defines conversion rules for converting data codes, and is a table that associates input codes and output codes. The control unit 11 converts the command code acquired from the chip 2 according to the conversion table 143 . Further, the control unit 11 converts write data read from the product DB 141 . The control unit 11 generates a transmission code including the converted command code and the converted write data, and transmits it to the chip 2 (step S35).

When acquiring a command code and a transmission code including write data from the server 1, the CPU 21 of the chip 2 compares the command code acquired from the server 1 with the command code converted in step S32 (step S36). That is, the CPU 21 compares the command code converted by itself with the command code converted by the server 1 to confirm (authenticate) the authenticity of the command code. Thereby, the CPU 21 performs an authentication process for authenticating the validity of the server 1 . The CPU 21 determines whether or not the command codes match (step S37). If it is determined that the command codes do not match (S37: NO), the CPU 21 discards the acquired data and terminates the series of processes.

When determining that the command codes match, the CPU 21 converts the write data included in the transmission code acquired from the server 1 according to the conversion table 143 (step S38). That is, the CPU 21 restores the write data converted by the server 1 . The CPU 21 stores the converted write data in the rich area 201 or the secure area 202 (step S39), and ends the series of processes.

In the above description, a series of manufacturing processes have been described separately for the chip manufacturer, the chip issuer, and the product manufacturer. not a thing For example, the chip manufacturer and the chip issuer may be the same business operator, and one business operator may perform the steps from manufacturing the chip 2 to issuing it. Also, one business operator may perform all the manufacturing work up to the assembly of the device.

As described above, according to the present embodiment, confidential information is held in the secure area 202, which is a software module in the chip 2, and arithmetic processing using the confidential information is performed in the secure area 202. Security of confidential information can be ensured. In particular, in this embodiment, direct communication (input/output of information) between the secure area 202 and the outside of the chip 2 is disabled. In order to do so, it is necessary to go through the rich region 201, and safety can be further strengthened. Also, since the secure area 202 is a software module, it can have higher arithmetic processing capability than a physical module such as an IC chip. Furthermore, since there is no need to mount a dedicated physical module such as SIM on the device, it contributes to space saving and power saving.

In addition, according to the present embodiment, it is possible to set prohibition of rewriting the secret information written in the chip 2 at the stage of issue, so that the secret information can be prevented from being tampered with after issuance.

Further, according to the present embodiment, when additional writing or rewriting of data is performed after issuance, authentication is performed using secret information (for example, command table 142, conversion table 143, etc.) written at the stage of issuance. , data can be written safely.

Further, according to this embodiment, data can be written remotely via the network N. FIG.

Further, according to the present embodiment, when writing data remotely, by converting the written data according to the conversion table 143 and then distributing the data, it is possible to cope with data interception, exploitation, etc. on the communication channel. .

Further, according to the present embodiment, a command code is shared between the server 1 and the chip 2, and authenticity verification (authentication) is performed by combining the command code and the conversion table 143, thereby increasing security. can increase

Further, according to the present embodiment, by rewriting the unique information 245 according to the request of the product maker or the like, it is possible to facilitate the management of the chip 2 by the product maker or the like.

The embodiments disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above-described meaning, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 server (information processing device)
11 Control Unit 12 Main Storage Unit 13 Communication Unit 14 Auxiliary Storage Unit P1 Program 141 Product DB
142 command table 143 conversion table 2 chip (control device)
21 CPUs
22 RAMs
23 input/output I/F
24 non-volatile memory 241 rich OS
242 Application 243 Secure OS
244 application 245 unique information 246 key information 247 authentication information

Claims (4)

A data writing method for writing data to a storage area of a control device,
The control device has a plurality of execution regions that mutually input and output information via a hypervisor,
causing the computer to execute a process of writing predetermined secret information into a second execution area, of the plurality of execution areas, to which access from the first execution area is restricted ;
the second execution region holds in advance unique information unique to the control device;
A data writing method , wherein the unique information is rewritten to a predetermined value . The control device comprises an input/output interface,
2. The data writing method according to claim 1, wherein said secret information is written into said second execution area configured such that direct input/output of information via said input/output interface is impossible. 3. The data writing method according to claim 1 , wherein data to be newly written in the second execution area is transmitted to the control device via a network. writing a conversion table defining data code conversion rules in the second execution area;
4. The data writing method according to claim 3 , wherein said data converted according to said conversion table is transmitted to said control device.

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