JPH1040095A - Security chip with built-in program execution memory - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a security chip for preventing illegal acts by duplicating a memory for storing a program after a chip mounted on a control board is certified. SOLUTION: A clock generation circuit 10, a central processing unit 1
1, built-in RAM 13, reset circuit 12, program execution memory 14, encrypted program storage memory 17,
It comprises a program decryption circuit 15 and a security check circuit 16. After the security check of the encrypted program, the decrypted user program (UP) is also checked, and controlled according to the program only in a normal case. In addition, the memory for storing by encryption is configured by a memory different from the chip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcomputer chip (hereinafter referred to as "chip") incorporating a program which has been inspected by a third-party accredited organization and is mounted on a control board of a pachinko or spinning machine. The present invention relates to a chip for preventing the certification program from being modified.

[0002]

2. Description of the Related Art In a conventional chip, when a gaming machine that controls a gaming machine based on a memory in which an authorized program is stored is initially turned on, is the program stored together with a key code in the memory valid? A security circuit mounted on the chip performs a security check on the integrity of the authentication code, and if the result of the check indicates that the security code is valid, the control program is allowed to operate, and the gaming machine is activated based on the program stored in the memory. A device configured to be controlled has been invented (JP-A-03-118120).

[0003]

In such a conventional chip, when a memory is replaced from an authorized authorized memory to an unauthorized memory, or when an internal program is modified after the authentication, an illegal act is detected and a gaming machine is detected. Operation can be disallowed. However, since the security circuit of such a chip is configured so that the security circuit starts when the power of the gaming machine is turned on, the security check is not performed after the security circuit is once activated, so that the following illegal acts are performed. May be performed. In other words, an illegal memory storing an unauthorized program is installed in parallel with the memory storing the authorized program, and when a security check is performed by the chip, the memory storing the authorized program is connected and the security check is performed. It is conceivable that the illegal operation is performed by the dual ROM system in which the operation is switched to the invalid memory after the termination and the control is performed based on the program stored in the invalid memory. Therefore, it is an object of the present invention to provide a safe chip capable of preventing such misconduct.

[0004]

That is, the present invention provides a central processing unit (CPU) connected to a clock generation circuit,
A built-in RAM connected to the CPU via a bus, a memory such as an EEPROM or a flash memory for executing a program, a reset circuit connected to a reset unit of the CPU, and an authenticated user program (UP) are encrypted. Memory for storing in an encrypted state, and an encrypted user program (U) stored in the storage memory.
P ′), a security check circuit for performing a security check when reading the data, a program decryption circuit for decrypting the encrypted user program (UP ′) when the security check circuit confirms that the program is legitimate, and the program decryption A program for storing a program decrypted by the circuit for controlling the gaming machine, and a program for executing control in accordance with a user program stored in the memory for program execution only in a normal case. Security chip with built-in execution memory. The invention according to claim 2 is that, after the security check of the encrypted program in the chip having the above configuration, the user program (UP) decrypted by the program decryption circuit is also security-checked, and the user program (UP) before and after decryption is performed. A security chip with a built-in program execution memory configured to control according to a program stored in the program execution memory only when the security check of UP) is normal. According to a third aspect of the present invention, the memory for storing the authenticated user program (UP) in an encrypted state is constituted by an external memory separate from the chip.

[0005]

In the security chip according to the present invention, the authorized user program (UP) and the security code (K1) are encrypted in advance, and the encrypted data and the security code (K2) for security-checking the encrypted data are encrypted. When the game machine is powered on, data comprising an encrypted user program (UP ') and a security code (K1') of the encrypted program stored in the encrypted program storage memory when the gaming machine is powered on. Is performed based on the security code (K2) to determine whether or not the program is legitimate, and if the result of the check is abnormal, the operation of the gaming machine is stopped via the reset circuit. If the result of the security check is determined to be normal, the encrypted user program (UP ') stored in the encrypted program storage memory and the security code (K1') of the encrypted program are sent to the program decryption circuit. The decoding process is performed there. It is installed in a program execution memory as a user program (UP) that has been verified by a third party inspection organization.
In the control board, the gaming machine is controlled while using the built-in RAM based on the user program (UP) installed in the program execution memory.

According to the second aspect of the present invention, in the security check circuit, an encrypted user program (U
P ′) and the encrypted security code (K1 ′) wo
After performing a security check on whether or not the program is legitimate based on the security code (K2), the user decrypts the user program (UP) after decrypting the decrypted code in the program decryption circuit into the program execution memory. ) Is again performed in the security check circuit based on the security code (K1), and as a result, if the program is not determined to be legitimate, the operation of the gaming machine is stopped via the reset circuit. When it is determined that the game machine is authorized, the gaming machine is controlled using the built-in RAM based on the program installed in the program execution memory.

Incidentally, data is encrypted (encryption).
As a method of performing this, a key code (key) is set, and this is set to DES (Data ebcryption Standard) in the United States or FEAL8 (Fast data Enciphermen
t Algorithm) or other standard.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. In FIG. 1, reference numeral 1 denotes a microcomputer chip (hereinafter referred to as a chip) mounted on a control board of a game machine. The chip 1 is a central processing unit (CPU) which receives data based on a clock signal generated by a clock generation circuit 10. CPU) 11 and the CPU 11
RAM 1 of a user application program connected via an internal data bus and an address bus
3 and a memory 14 such as an EEPROM for executing a program for installing an application program of a user, a memory 14 such as an EEPROM, a program decryption circuit 15 for decrypting encrypted data based on a predetermined key code (key); A security check is performed based on a predetermined security code (K2) on data in an encryption program storage memory 17 that stores a user application program that has been inspected by a third party inspection organization encrypted based on a predetermined key code. A security check circuit 16; and a reset circuit 12 for resetting the CPU 11 based on a transmission signal from the security check circuit 16. The program decryption circuit 15, the reset circuit 12, and the program execution memory 1 Door is connected.

FIG. 2 shows a second embodiment of the present invention. In the chip of the first embodiment, a user program (UP) stored in a program execution memory 14 is provided with a predetermined security. The security circuit 16 performs a security check based on the code (K1).

FIG. 3 shows a third embodiment of the present invention, in which the above-mentioned memory 37 with a built-in encryption program is built in the chip 1, and a legitimate program which has been verified by a third party inspection organization is used for security. This is configured to be stored in an encrypted state together with the code (K1) via the write circuit 38. Since other configurations are the same as those of the second embodiment, the same reference numerals are used and the description is omitted. .

In the above-described configuration, in the chip according to the present embodiment, as shown in FIG. 4, the program of the gaming machine developed by the user (hereinafter referred to as a user program (UP)) is verified by a third party inspection organization. After that, a security code calculated based on the user program (UP) is given. The user program (UP) and the security code (K1) are encrypted based on a predetermined key code (key) and installed in the encryption program storage memory 17 together with the security code (K2) of the encrypted data. An encrypted user program (UP ′) and a security code (K1 ′) and a security code (K2) for encryption are installed in the built-in memory 37 of the third embodiment via a writing circuit 38. Thus, the state of the chip on the control board is obtained.

In this state, when the power of the chip is turned on, the security check circuit 16 first performs a security check by scanning data of each address based on the security code (K2). When an error is found in the data as a result of the security check, a reset command is transmitted to the reset circuit 12 and the CPU 1
1 is stopped. On the other hand, when it is determined that the data is correct, the encrypted user program (UP ') and the security code (K1') are sent to the program decryption circuit 15 and the data of each address is decrypted based on a predetermined encryption code (key). The decrypted user program (UP) and security code (K1) are installed in the program execution memory 14 inside the chip 1. In the chip of the first embodiment, the CPU 11 controls the gaming machine while reading the user program (UP) stored in the program execution memory 14.

In the chips 1 of the second and third embodiments, the user program (UP) and the security code (K1) stored in the program execution memory 14 are stored.
The security check circuit 16 again performs a security check based on the above, and determines whether or not the decrypted program is legitimate. As a result, when the data does not match in the security check of the user program (UP), it is determined that the user program (UP) stored in the memory 14 is not proper and the reset circuit 12 resets the CPU 11. Stop the operation of the gaming machine. If the data matches in the security check, it is determined that the program is legitimate, and the CPU 11
The game machine is controlled while loading the program into the computer 13.

As described above, the microcomputer chip according to the present invention is configured to operate by installing an encrypted user program (UP ') in an internal memory by decrypting the encrypted user program (UP'). Therefore, it is possible to prevent an illegal act such as switching and using the dual ROM. Further, in the chip according to the present invention, since a program certified by a third party inspection organization is installed in the memory in a state of being encrypted based on a predetermined key code, a person other than the developer easily analyzes the program. Such an action can be prevented beforehand. Further, since the user machine (UP) is installed in the program execution memory built in the chip, the gaming machine is controlled, so that the game machine is controlled.
Since information is exchanged via a high-speed and stable circuit such as an internal bus, the influence of noise and malfunction can be minimized. Furthermore, in a configuration in which security checks are performed for both the encrypted user program (UP ') and the decryption program (UP), the decryption program ( Since the security check of (UP) determines whether the program is legitimate or not, it is substantially impossible to modify the program in a state where both security checks are passed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a microcomputer chip according to the present invention.

FIG. 2 is a block diagram showing a second embodiment of the microcomputer chip according to the present invention.

FIG. 3 is a block diagram showing a third embodiment of the microcomputer chip according to the present invention.

FIG. 4 is a conceptual diagram showing the states of data stored in a memory of a user program (UP), an encrypted program storage memory, and a program execution memory that have been certified by a third party inspection organization.

[Explanation of symbols]

 1 Chip 10 Clock Generation Circuit 11 CPU 12 Reset Circuit 13 Built-in RAM 14 Program Execution Memory 15 Program Decryption Circuit 16 Security Check Circuit 17, 37 Encrypted Program Storage Memory 38 Write Circuit

Claims (3)

[Claims] 1. A central processing unit (CPU) connected to a clock generation circuit, a built-in RAM connected to the CPU via a bus, a memory such as a flash memory for program execution, an EEPROM, etc., and a reset of the CPU. A reset circuit connected to the unit, a memory for storing the authenticated user program (UP) in an encrypted state, and security when reading the encrypted user program (UP ') stored in the storage memory A security check circuit for performing a check, a program decryption circuit for decrypting an encrypted user program (UP ′) when the security check circuit determines that the program is authentic, and a program decrypted by the program decryption circuit. Memory for program execution stored for gaming machine control Becomes, program execution memory enclosing the security chip, characterized in that it is configured to control in accordance with legitimate only if the program stored in memory for execution the program. 2. A central processing unit (CPU) connected to a clock generation circuit, a built-in RAM connected to the CPU via a bus, a memory such as a flash memory for program execution, and an EEPROM, and a reset of the CPU. A reset circuit connected to the unit, a memory for storing the authenticated user program (UP) in an encrypted state, and security when reading the encrypted user program (UP ') stored in the storage memory A security check circuit for performing a check, a program decryption circuit for decrypting an encrypted user program (UP ′) when the security check circuit determines that the program is authentic, and a program decrypted by the program decryption circuit. Memory for program execution stored for gaming machine control After the security check of the encrypted program, a security check is also performed on the user program (UP) decrypted by the program decryption circuit, and only when the security check of the user program (UP) before and after decryption is normal. A security chip with a built-in program execution memory, wherein the security chip is configured to control according to a program stored in the program execution memory. 3. The authenticated user program (U)
3. The security chip with a built-in program execution memory according to claim 1, wherein the memory for storing P) in an encrypted state is a memory different from the chip.