JP2007249996A - Program development support apparatus and program implementation method - Google Patents

Abstract

A development environment with a high security level is provided for a key implementation system.
For a system having an LSI having a secure memory, a program is developed by setting an LSI having a common configuration to a <development mode> different from the <product operation mode>. In addition, the <administrator mode> is set to develop and encrypt the key generation program, and the <key generation mode> is set to execute the encrypted key generation program to generate various keys.
[Selection] Figure 2

Description

  The present invention belongs to a technology related to development and program implementation of a key-implemented system and an LSI used for the system.

  Japanese Patent Application No. 2001-286881 discloses a technique for improving the confidentiality and secrecy of a key in a key mounting system as compared with the prior art.

  In the system as described above, how to maintain security is a major issue in the program development process and the mounting process.

  The present invention proposes a program development method and environment or a program implementation method with a high security level for the system as described above.

  The solution provided by the invention of claim 1 is a program development support apparatus for supporting the development of an encrypted program, an LSI having the same configuration as the LSI on which the encrypted program operates, an external memory for storing a plaintext program, The LSI includes a secure memory storing shared key information relating to a raw shared key, and obtaining a raw shared key from the shared key key information stored in the secure memory; and And a second step of encrypting a plaintext program input from an external memory using the raw shared key.

  According to the first aspect of the present invention, an LSI having the same configuration as the LSI on which the encryption program to be developed operates is provided as the development environment. In this LSI, a raw shared key is obtained from the shared key key information stored in the secure memory, and a plain text program input from the external memory is encrypted using the raw shared key. That is, decryption of the raw shared key and encryption of the plaintext program using this raw shared key can be executed. Therefore, the plaintext program can be encrypted without the program developer knowing the raw shared key.

  The solution provided by the invention of claim 2 comprises an LSI and an external memory for storing a plaintext program as a program development support apparatus for supporting the development of an encrypted program, and the LSI is a shared shared key. A secure memory that stores key key information and a boot ROM that stores a boot program, and by executing the boot program stored in the boot ROM, from the shared key key information stored in the secure memory A first step of obtaining a raw shared key and a second step of encrypting a plaintext program input from the external memory using the raw shared key are executed.

  According to the invention of claim 2, by executing the boot program in the LSI, the raw shared key is obtained from the shared key key information stored in the secure memory, and the plaintext program input from the external memory is converted to the raw shared key. It is encrypted using That is, the decryption of the raw shared key and the encryption of the plaintext program using the raw shared key are executed by the boot program instead of an instruction from the outside. For this reason, encryption of the plaintext program can be executed while reliably preventing the program developer from knowing the raw shared key.

  According to a third aspect of the invention, in the first or second aspect, the shared key key information includes an encrypted shared key obtained by encrypting a raw shared key with a raw first intermediate key, and a raw second intermediate key. An encrypted first intermediate key encrypted with an intermediate key, and the first step uses the encrypted shared key, the encrypted first intermediate key, and a program encryption type to generate the raw shared key. Is to be decrypted.

  According to a fourth aspect of the present invention, there is provided a means for implementing an encryption program in a key mounting system having an LSI having a secure memory and an external memory, wherein the shared key key information relating to the raw shared key is stored in the secure memory. Initial value setting processing for storing unique key key information related to a raw unique key, a first step of obtaining a raw shared key from shared key key information stored in the secure memory in the LSI, and the LSI A second step of decrypting the shared key encryption program given from the external memory using the raw shared key obtained in the first step; and a unique step stored in the secure memory in the LSI A third step of obtaining a raw unique key from the key-key information; and the third step in which the plaintext program obtained in the second step is obtained in the LSI. Using the obtained raw inherent key and a fourth step of encrypting the inherent key encryption program obtained in said fourth step is to mount the external memory.

  According to the invention of claim 4, the shared key encryption program given to the LSI is decrypted using the raw shared key obtained from the shared key key information stored in the secure memory. The decrypted plaintext program is encrypted using the raw unique key obtained from the unique key key information stored in the secure memory. That is, the key to be encrypted by the shared key encryption program is converted from the shared key to the unique key and installed in the system. For this reason, in each product held by the user, a program encrypted with a different unique key is mounted, and the secrecy is improved. In addition, even if the encryption is broken, the number of products that are damaged is limited, and the security is higher than before.

  According to a fifth aspect of the present invention, the LSI according to the fourth aspect includes a boot ROM for storing a boot program, and the first to fourth steps are performed by causing the LSI to execute the boot program stored in the boot ROM. Shall be executed.

  In the invention of claim 6, the unique key information in claim 4 is stored in the non-rewritable area of the secure memory.

  In the invention of claim 7, the shared key key information in claim 4 is obtained by encrypting the raw shared key with the raw first intermediate key and encrypting the raw first intermediate key with the raw second intermediate key. The encrypted first intermediate key is encrypted, and the first step is to decrypt the raw shared key using the encrypted shared key, the encrypted first intermediate key, and the program encryption type. .

  In the invention of claim 8, the unique key key information in claim 4 includes an encrypted unique key obtained by encrypting the raw unique key with the raw first intermediate key, and the raw first intermediate key encrypted with the raw second intermediate key. The encrypted first intermediate key is included, and the third step is to decrypt the raw unique key using the encrypted unique key, the encrypted first intermediate key, and the program encryption type. .

  In the invention of claim 9, the unique key information in claim 4 is a unique ID unique to the LSI.

  As described above, according to the present invention, an LSI having a secure memory including a non-rewritable area and having high secrecy is used as a program development environment by changing its operation mode from the mounting mode to the development mode. Security in the development environment can be increased compared to the past.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, an encrypted key or program obtained by encrypting X (key or program) using the key Y is expressed as Enc (X, Y).

  FIG. 1 is a block diagram showing the internal configuration of a secure LSI according to this embodiment. In FIG. 1, the secure LSI 1 is configured to be connectable to an external memory (flash memory) 100, an external tool 110, and the like via an external bus 120. In addition, the operation mode can be set by giving the mode ID.

  The main components related to this embodiment will be briefly described.

  First, the secure LSI 1 includes a secure memory (secure flash) 10 including a non-rewritable area 11. In this non-rewritable area 11, a non-rewritable area write flag 12 is provided. When the mode ID is once written in the secure memory 10, the flag value of the non-rewritable area write flag 12 changes from “permitted” to “done”, and subsequent writing to the non-rewritable area becomes impossible. In the present embodiment, the secure memory 10 and the external memory 100 are configured by flash memory, but of course, the present invention is not limited to this, and any non-volatile memory may be used. Absent.

  The secret key calculation processing unit 20 includes a register for storing various keys and program encryption types, and executes encryption processing. The key generation / update sequencer 30 has a mode ID storage register 31, and can generate an operation of the secret key calculation processing unit 20, that is, various keys according to the mode ID stored in the mode ID storage register 31. Control whether or not. Also, an encryption type identifier storage register 32 for storing an encryption type identifier indicating what algorithm and key length the key or program is encrypted with is provided. Further, a program encryption type 33 is implemented.

  The mode sequencer 40 also includes a mode ID storage register 41, and the operation of the external host interface (I / F) 50 according to the mode ID stored in the mode ID storage register 41 and the value of the jumper 43, that is, The I / F through which the program or data stored in the external memory 100 is read is controlled. Thereby, it is possible to control whether or not the plaintext program stored in the external memory 100 can be executed. Furthermore, the mode sequencer 40 includes an encryption type identifier storage register 42 that stores an encryption type identifier indicating which method is used to encrypt the key.

  Under the control of the mode sequencer 40, the external host I / F 50 includes a through unit 52, a delay unit 53, a program decryption cryptographic engine 54, and a through unit 56, content encryption / A program or data is input / output to / from the external memory 100 or the external tool 110 via any one of the decryption cryptographic engines 57.

  Here, except for an administrator mode to be described later, a program input via the through unit 52 is not executed inside the secure LSI 1. That is, the through unit 52 is effective when encrypting a plain text program or re-encrypting an already encrypted program using another key. The secure LSI 1 performs an administrator mode described later. Except for this, the operation is not shifted to the program input via the through unit 52. Therefore, for example, even if the secure LSI 1 that has become a product takes in the plain text program via the through unit 52, it cannot be executed. Note that when executing a plain text program, the secure LSI 1 inputs the program therein via the delay unit 53.

  The boot ROM 60 stores a boot program that controls the startup operation of the secure LSI 1. The HASH calculation unit 70 calculates a HASH value in order to verify the validity of the program read into the secure LSI 1.

  The external memory 100 stores programs and contents. The external tool 110 stores various initial values stored in the secure memory 10 when the secure LSI 1 is first activated. The type of the initial value varies depending on the set operation mode.

  FIG. 2 is a diagram showing the overall flow of development and commercialization using the secure LSI 1 of FIG. As shown in FIG. 2, the secure LSI 1 has four modes: an administrator mode (mode ID: 00), a key generation mode (mode ID: 01), a development mode (mode ID: 10), and a product operation mode (mode ID: 11). Operates in various operation modes.

  First, the secure LSI 1 set to the administrator mode operates as an administrator LSI. In the administrator LSI, a key generation program is developed, and the key generation program is encrypted using an arbitrary key generation key.

  The secure LSI 1 set to the key generation mode operates as a key generation LSI. In the key generation LSI, an encrypted key generation program generated in the administrator LSI is mounted, and various keys are generated by executing the key generation program.

  The secure LSI 1 set to the development mode operates as a development LSI. In the development LSI, an application program to be executed by an actual product is developed. Then, the application program is encrypted using the program shared key.

  The secure LSI 1 set in the product operation mode operates as an actual product LSI. In the product LSI, the application program generated by the development LSI and encrypted with the program shared key is mounted and converted into the application program encrypted with the program unique key. Note that this conversion process can be executed even in the development LSI for debugging the application program.

  Hereinafter, details of the operation of the secure LSI 1 in each mode will be described with reference to a flowchart and a data flow. The secure LSI 1 performs the following operation by executing the boot program stored in the boot ROM 60.

  FIG. 3 is a flowchart showing the overall processing flow of the boot program. When the secure LSI 1 is turned on, the boot program stored in the boot ROM 60 is executed by the CPU 65. As shown in FIG. 3, first, each hardware is initialized (SZ0). Then, various initial values are read from the external tool 110 and set in the secure memory 10 (SZ1).

  FIG. 22 is a flowchart of the initial value setting process SZ1. First, the jumper 44 determines whether or not the secure memory 10 is mounted in the LSI. Next, it is determined whether or not the non-rewritable area write flag 12 is “completed”. If it is “completed”, the initial value has already been set in the secure memory 10, and the process SZ1 is terminated. When the non-rewritable area write flag 12 is “permitted”, the initial value is written into the secure memory 10. In addition to the mode ID, the encrypted program unique key, address management information, and data unique key are written in the non-rewritable area 11 of the secure memory 10. As a result of the initial determination, when it is determined that the secure memory 10 is outside the LSI, the mode ID is overwritten with a value representing the product operation mode. Thereby, an unauthorized product in which the secure memory 10 is outside the LSI package can operate only in the product operation mode.

  Next, the unwritable area write flag 12 is set to “done”. This makes it impossible to rewrite the non-rewritable area 11 thereafter. Further, the encryption type identifier and the implementation mode flag are written in the normal areas 13 and 14. When the mode ID indicates a mode other than the administrator mode, an encrypted shared key / key generation key is also written in the normal areas 13 and 14 in addition to these.

  Thereafter, pre-processing SZ2 is executed. FIG. 4 is a data flow of the preprocessing SZ2. Here, the mode ID set in the non-writable area 11 of the secure memory 10 is set in the mode ID storage register 31 of the key generation / update sequencer 30 and the mode ID storage register 41 of the mode sequencer 40. In addition, the encryption type identifier set in the first normal area 13 of the secure memory 10 is set in the encryption type identifier storage register 32 of the key generation / update sequencer 30 and the encryption type identifier storage register 42 of the mode sequencer 40. The Furthermore, the address management information stored in the non-rewritable area 11 of the secure memory 10 is set in the encryption address section storage register 81 of the MEMC 80. The operations so far correspond to the initial value setting phases PA0, PB0, PC0, PD0 in FIG.

  Thereafter, the operation in each mode is performed according to the value of the mode ID (SZ3).

<Administrator mode>
When the mode ID is “00”, the secure LSI 1 is in the administrator mode and executes the plaintext program execution process SA1 or the program encryption process SA2 according to the value of the jumper 43 (SA0).

  In the key generation program development phase PA1, a plain text program execution process SA1 is performed, where a key generation program is generated. This key generation program is stored in the external memory 100.

  In the key generation program encryption phase PA2, first, the given key generation key is encrypted by executing the key generation program as shown in the data flow of FIG. That is, in the external host I / F 50, the mode sequencer 40 enables the through unit 52 of the program processing unit 51. Then, the key generation program stored in the external memory 100 is given to the CPU 65 via the through unit 52 and executed. By executing this key generation program, the key generation key stored in the external memory 100 is encrypted by the secret key calculation processing unit 20 using the program encryption type installed in the key generation / update sequencer 30. .

  In the present embodiment, the encryption of the key is performed using the first intermediate key and the second intermediate key. That is, as a result of encryption, an encryption key (here, Enc (key generation key, MK1)) obtained by encrypting a plaintext key (here, key generation key) with the first intermediate key (here, MK1), and the first intermediate key An encrypted first intermediate key (here, Enc (MK1, CK)) obtained by encrypting the key with the second intermediate key (here, CK) is obtained. Of course, the present invention is not limited to such a key encryption method.

  Thereafter, the program encryption process SA2 is executed. FIG. 6 is a flowchart of the program encryption process SA2, and FIG. 7 is a data flow. First, the encrypted key generation key Enc (key generation key, MK1) and Enc (MK1, CK) stored in the external memory 100 are transferred to the private key via the through unit 52 of the external host I / F 50. Set in the arithmetic processing unit 20 (SA21). Then, the encrypted key generation key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain a key generation key (SA22). Thereafter, the plaintext key generation program stored in the external memory 100 is taken in, encrypted using the key generation key decrypted in SA22, and written in the external memory 100 (SA23). Further, the HASH calculation unit 70 performs HASH calculation on the plaintext key generation program in the external memory 100, and writes the calculated HASH value in the external memory 100 (SA24).

  By such an operation, in the administrator mode, the key generation program Enc (key generation program, key generation key) encrypted with the key generation key and the encrypted key generation key Enc (key generation key, MK1), Enc ( MK1, CK) and the HASH value of the key generation program are generated.

<Key generation mode>
When the mode ID is “01”, the secure LSI 1 enters the key generation mode, and executes the key generator manufacturing process SB1 or the key management / issue process SB2 according to the value of the mounting mode flag (SB0).

  In the key generator manufacturing phase PB1, the key generator manufacturing process SB1 is executed. FIG. 8 is a flowchart of the process SB1, and FIGS. 9 and 10 are data flows. Here, the through unit 52 is set to be effective in the program processing unit 51 of the external host I / F unit 50 according to the value of the mode ID and the mounting mode flag.

  First, the encrypted program unique key Enc (program unique key, MK0) and Enc (MK0, CK) stored in the non-writable area 11 of the secure memory 10 are stored in the encryption key storage register of the secret key calculation processing unit 20. (SB11). Then, the encrypted program unique key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program unique key (SB12). Next, the encrypted key generation key Enc (key generation key, MK1) and Enc (MK1, CK) set in the initial value setting phase PB0 are set in the encryption key storage register of the secret key calculation processing unit 20. (SB13) The encrypted key generation key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain a key generation key (SB14).

  Thereafter, the key generation program Enc (key generation program, key generation key) encrypted with the key generation key stored in the external memory 100 is passed through the through unit 52 of the program processing unit 51 of the external host I / F 50. Through the private key calculation processing unit 20 (SB15). The captured encrypted key generation program is decrypted with the key generation key, and then encrypted with the program unique key to obtain an encrypted key generation program Enc (key generation program, program unique key) (SB16). . And it writes in the external memory 100 (SB17). Next, the HASH value stored in the external memory 100 is set in the normal area 13 of the secure memory 10 via the through unit 52 (SB18).

  Further, the value of the mounting mode flag stored in the normal area 13 of the secure memory 10 is set to “OFF” by the CPU 65 (SB19). Then, the encrypted key generation key Enc (key generation key, MK1), Enc (MK1, CK) stored in the normal area 13 of the secure memory 10 is deleted (SB1A) and stored in the external memory 100. The encrypted key generation program Enc (key generation key program, key generation key) and the HASH value that have been deleted are deleted (SB1B).

  In the key management / issue phase PB2, key management / issue processing SB2 is executed. FIG. 11 is a flowchart of the process SB2, and FIGS. 12 and 13 are data flows. Here, the encryption engine 54 for program decryption included in the external host I / F unit 50 is set to be valid by the value of the mode ID and the implementation mode flag. First, the encrypted program unique key Enc (program unique key, MK0) and Enc (MK0, CK) stored in the non-writable area 11 of the secure memory 10 are stored in the encryption key storage register of the secret key calculation processing unit 20. (SB21). Then, the encrypted program unique key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program unique key (SB22). The obtained program unique key is set in the program unique key storage register of the program decryption cryptographic engine 54 of the external host I / F 50 (SB23).

  After that, the key decryption program Enc (key generation program, program unique key) encrypted in the external memory 100 and encrypted with the program unique key is used for the program decryption encryption of the program processing unit 51 of the external host I / F 50. Decoding is performed via the engine 54, and the data is taken into the HASH calculation unit 70 to calculate the HASH value (SB24). Then, the calculated HASH value is compared with the HASH value stored in the normal area 13 of the secure memory 10 to check whether the key generation program has been tampered with (SB25). When the HASH values match (No in SB26), the process shifts to the key generation program Enc (key generation program, program unique key) stored in the external memory 100, and key generation is executed (SB27). . On the other hand, when the HASH values do not match (Yes in SB26), it is presumed that some kind of fraud has been performed, and processing by the unauthorized access time control is executed (SB28).

  In the key generation mode, the plain text program is executed because only the program is input with the through unit 52 enabled or the encrypted program encrypted with the program decryption encryption engine 54 enabled. Thus, the operation of the secure LSI 1 is limited.

<Development mode>
When the mode ID is “10”, the secure LSI 1 is in the development mode, and depending on the value of the jumper 43 (SC0), the program encryption process SC1, the plaintext program execution process SC2, the program implementation process SC3, or the encryption program execution Process SC4 is executed.

  In the application program development phase PC1, the plaintext program execution process SC2 is performed with the delay unit 53 enabled, and the application program is developed. The developed application program is stored in the external memory 100.

  In the application program encryption phase PC2, program encryption processing SC1 is executed. FIG. 14 is a flowchart of the program encryption process SC1, and FIG. 15 is a data flow. First, the encrypted program shared key Enc (program shared key, MK2), Enc (MK2, CK) as shared key key information stored in the normal area 14 of the secure memory 10 is set in the secret key calculation processing unit 20 (SC11). Then, the encrypted program shared key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program shared key (SC12). Thereafter, the plaintext application program stored in the external memory 100 is taken in, encrypted using the program shared key decrypted in SC12, and written in the external memory 100 (SC13). Further, HASH calculation is performed by the HASH calculation unit 70 on the plain text application program in the external memory 100, and the calculated HASH value is written in the external memory 100 (SC14).

  By such an operation, the application program Enc (application program, program shared key) encrypted with the program shared key and the HASH value of the application program are generated.

  Next, in the application program mounting phase PC3, the program mounting process SC3 is executed, and in the application program debugging phase PC4, the encrypted program execution process SC4 is executed. Since these processes are the same as the processes SD1 and SD2 in the product operation mode, details will be described later.

  As described above, the LSI 1 having the secure memory 10 including the non-rewritable area 11 and having high secrecy is used as a program development environment by changing the operation mode from the mounting mode to the development mode. Can be increased as compared with the prior art.

  In addition, since the raw shared key is decrypted from the encrypted shared key as the shared key key information stored in the secure memory 10 and the plaintext program is encrypted using this raw shared key, program development is performed. The plaintext program can be encrypted without the person knowing the raw shared key.

  In addition, since decryption of the raw shared key and encryption of the plaintext program using this raw shared key are performed by the boot program, not by an external instruction, the plaintext program is encrypted to the program developer. It can be executed while reliably preventing the raw shared key from being known.

<Product operation mode>
When the mode ID is “11”, the secure LSI 1 is in the product operation mode, and executes the program mounting process SD1 or the normal boot process SD2 according to the value of the mounting mode flag (SD0).

  In the product mounting phase PD1, program mounting processing SD1 is executed. FIG. 16 is a flowchart of the process SD1, and FIGS. 17 and 18 are data flows. Here, the through unit 52 is set to be effective in the program processing unit 51 of the external host I / F unit 50 according to the value of the mode ID and the mounting mode flag.

  First, the encrypted program unique key (program unique key, MK0) and Enc (MK0, CK) as unique key key information stored in the non-writable area 11 of the secure memory 10 are stored in the secret key calculation processing unit 20. The encryption key storage register is set (SD11). Then, the encrypted program unique key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program unique key (SD12). Next, the encrypted program shared key Enc (program shared key, MK2), Enc (MK2, CK) as shared key key information set in the initial value setting phase PD0 is encrypted by the secret key calculation processing unit 20. It is set in the key storage register (SD13), and the encrypted program shared key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program shared key (SD14).

  Thereafter, the application program Enc (application program, program shared key) encrypted with the program shared key stored in the external memory 100 is passed through the through unit 52 of the program processing unit 51 of the external host I / F 50. The secret key calculation processing unit 20 takes in (SD15). The captured encrypted application program is decrypted with the program shared key and then encrypted with the program unique key to obtain an encrypted application program Enc (application program, program unique key) (SD16). And it writes in the external memory 100 (SD17). Next, the HASH value stored in the external memory 100 is set in the normal area 13 of the secure memory 10 via the through unit 52 (SD18).

  Further, the value of the mounting mode flag stored in the normal area 13 of the secure memory 10 is set to “OFF” by the CPU 65 (SD19). Then, the encrypted program shared key Enc (program shared key, MK1), Enc (MK1, CK) stored in the normal area 13 of the secure memory 10 is deleted (SD1A) and stored in the external memory 100. The encrypted application program Enc (application program, program shared key) and HASH value that have been deleted are deleted (SD1B).

  That is, the key to be encrypted by the shared key encryption program is converted from the shared key to the unique key and installed in the system. For this reason, in each product held by the user, a program encrypted with a different unique key is mounted, and the secrecy is improved. In addition, even if the encryption is broken, the number of products that are damaged is limited, and the security is higher than before.

  The unique key may be generated based on the unique ID. That is, for each secure LSI 1, an individual unique ID is mounted in the secure memory 10 as unique key key information, and in this product mounting phase PD1, a unique key is generated from the mounted unique ID by the boot program. May be.

  In the product operation phase PD2, the normal boot process SD2 is executed. FIG. 19 is a flowchart of the process SD2, and FIGS. 20 and 21 are data flows. Here, the encryption engine 54 for program decryption included in the external host I / F unit 50 is set to be valid by the value of the mode ID and the implementation mode flag.

  First, the encrypted program unique key Enc (program unique key, MK0) and Enc (MK0, CK) stored in the non-writable area 11 of the secure memory 10 are stored in the encryption key storage register of the secret key calculation processing unit 20. (SD21). Then, the encrypted program unique key is decrypted using the program encryption type installed in the key generation / update sequencer 30 to obtain the program unique key (SD22). The obtained program unique key is set in the program unique key storage register of the program decryption cryptographic engine 54 of the external host I / F 50 (SD23).

  Thereafter, the data unique ID stored in the unwritable area 11 of the secure memory 10 is set in the unique ID storage register of the secret key calculation processing unit 20 (SD24). Further, a random number is generated by the CPU 65 and set in a random number storage register of the secret key calculation processing unit 20 (SD25). Then, the secret key calculation processing unit 20 generates a data unique key from the data unique ID and the random number (SD26).

  After that, the application decryption encryption engine 54 of the program processing unit 51 of the external host I / F 50 stores the application program Enc (application program, program unique key) encrypted in the external memory 100 and encrypted with the program unique key. And is fetched into the HASH calculation unit 70 to calculate the HASH value (SD27). Then, the calculated HASH value is compared with the HASH value stored in the normal area 13 of the secure memory 10 to check whether the application program has been tampered with (SD28). When the HASH values match (No in SD29), the process is shifted to the application program Enc (application program, program unique key) stored in the external memory 100, and the application is executed (SD2A). On the other hand, when the HASH values do not match (Yes in SD29), it is presumed that some kind of fraud has been performed, and processing by the unauthorized access time control is executed (SD2B).

  In the merchandise operation mode, the plain text program is executed because only the program is input with the through section 52 enabled or the encrypted program encrypted with the program decryption encryption engine 54 enabled. Thus, the operation of the secure LSI 1 is limited.

  Note that, in the development mode and the product operation mode, even if a process for generating a key using the secret key calculation processing unit 20 is executed from the outside, it is determined by the key generation / update sequencer 30 and is not executed. In other words, the key generation / update sequencer 30 restricts the operation in the development mode and the product operation mode so that the program encryption type cannot be used except at the time of start-up, so the key generation processing cannot be executed. .

  In the present embodiment, programs and data are stored in the external memory 100, and initial values mounted in the secure memory 10 are stored in the external tool 110. It doesn't matter. For example, there is no problem even if a program or data is read from the external tool 110 and re-encrypted.

  In this embodiment, each process is executed by a boot program. However, the present invention is not limited to this, and a part or all of the process may be executed by other means. . However, security can be further enhanced by executing processing by a boot program instead of an instruction from the outside.

1 is a block diagram showing a configuration of a secure LSI according to an embodiment of the present invention. It is a figure showing the whole flow of development and commercialization using the secure LSI of FIG. It is a flowchart which shows the flow of the whole process of a boot program. It is a data flow of pre-processing SZ2. It is a data flow of encryption of a key generation key. It is a flowchart of program encryption process SA2. It is a data flow of program encryption process SA2. It is a flowchart of the key generator manufacturing process SB1 in the key generation mode. It is a data flow of key generator manufacturing process SB1. It is a data flow of key generator manufacturing process SB1. It is a flowchart of the key management / issue process SB2 in the key generation mode. It is a data flow of key management / issue process SB2. It is a data flow of key management / issue process SB2. It is a flowchart of program encryption processing SC1 in the development mode. It is a data flow of program encryption processing SC1. It is a flowchart of program mounting processing SD1 in the product operation mode. It is a data flow of program mounting process SD1. It is a data flow of program mounting process SD1. It is a flowchart of normal boot processing SD2 in the product operation mode. It is a data flow of normal boot processing SD2. It is a data flow of normal boot processing SD2. It is a flowchart of initial value setting processing SZ1.

Explanation of symbols

10 Secure Memory 11 Non-Rewritable Area 12 Non-Rewritable Area Write Flag 20 Secret Key Operation Processing Unit 30 Key Generation / Update Sequencer 31 Mode ID Storage Register 32 Encryption Type Identifier Storage Register 33 Program Encryption Type 40 Mode Sequencer 41 Mode ID Storage Register 42 Encryption Type identifier storage register 50 External host I / F
51 Program Processing Unit 52 Through Unit 53 Delay Unit 54 Decryption Encryption Engine 55 Data Processing Unit 56 Through Unit 57 Content Encryption / Decryption Encryption Engine 60 Boot ROM
70 HASH operation unit 100 External memory

Claims (9)

A program development support apparatus for supporting development of an encryption program,
An LSI having the same configuration as the LSI on which the encryption program operates;
An external memory for storing plaintext programs,
The LSI is
A secure memory storing shared key information related to the raw shared key, and
A first step of obtaining a raw shared key from the shared key key information stored in the secure memory;
A program development support apparatus configured to be capable of executing a second step of encrypting a plaintext program input from the external memory using the raw shared key. A program development support apparatus for supporting development of an encryption program,
An LSI and an external memory for storing a plaintext program;
The LSI is
A secure memory storing shared key information related to the raw shared key;
A boot ROM for storing a boot program, and
By executing a boot program stored in the boot ROM,
A first step of obtaining a raw shared key from the shared key key information stored in the secure memory;
And a second step of encrypting a plaintext program input from the external memory using the raw shared key. In claim 1 or 2,
The shared key key information includes an encrypted shared key obtained by encrypting a raw shared key with a raw first intermediate key, and an encrypted first intermediate key obtained by encrypting the raw first intermediate key with a raw second intermediate key. Including
The program development support apparatus, wherein the first step is to decrypt the raw shared key using the encrypted shared key, the encrypted first intermediate key, and a program encryption type. A method of mounting an encryption program in a key mounting system having an LSI having a secure memory and an external memory,
An initial value setting process for storing, in the secure memory, shared key information relating to a raw shared key and unique key key information relating to a raw unique key;
A first step of obtaining a raw shared key from the shared key key information stored in the secure memory in the LSI;
A second step of decrypting the shared key encryption program given from the external memory using the raw shared key obtained in the first step in the LSI;
In the LSI, a third step of obtaining a raw unique key from unique key key information stored in the secure memory;
A fourth step of encrypting the plaintext program obtained in the second step using the raw unique key obtained in the third step in the LSI;
A program mounting method comprising mounting the unique key encryption program obtained in the fourth step in the external memory. In claim 4,
The LSI includes a boot ROM for storing a boot program,
A program mounting method, wherein the first to fourth steps are executed by causing the LSI to execute a boot program stored in the boot ROM. In claim 4,
The program mounting method, wherein the unique key key information is stored in a non-rewritable area of the secure memory. In claim 4,
The shared key key information includes an encrypted shared key obtained by encrypting a raw shared key with a raw first intermediate key, and an encrypted first intermediate key obtained by encrypting the raw first intermediate key with a raw second intermediate key. Including
The program mounting method characterized in that the first step is to decrypt the raw shared key using the encrypted shared key, the encrypted first intermediate key, and a program encryption type. In claim 4,
The unique key key information includes an encrypted unique key obtained by encrypting a raw unique key with a raw first intermediate key, and an encrypted first intermediate key obtained by encrypting the raw first intermediate key with a raw second intermediate key. Including
The program mounting method characterized in that the third step is to decrypt the raw unique key using the encrypted unique key, the encrypted first intermediate key, and the program encryption type. In claim 4,
The program mounting method, wherein the unique key / key information is a unique ID unique to the LSI.

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