KR0175027B1 - Micro computer security method and device - Google Patents

Abstract

The present invention relates to a security method and apparatus for a microcomputer, and more particularly, to a security method and apparatus for data protection of a microcomputer.

The microsecurity device of the present invention includes a clock comparator which compares the counted value of the clock counter and a unique value of the microcomputer system, and outputs a synchronous clock if it matches, and a key code section having unique key data accessing the memory in the microcomputer. The clock code unit is coded by the number of synchronous clocks generated by the click comparison unit, and is input externally by the user to release the security device of the microcomputer. A key data buffer that stores key data, and key data stored in the data buffer and key data of the key code section are compared at a predetermined synchronous click corresponding to the code value of the clock code section, and if the key data is read and written to the microcomputer memory, the key is allowed. Including a code detector According to the present invention, it is possible to enhance the security of the system by allowing the key code that can access the memory of the microcomputer to be detected only at a specific time.

Description

Micro computer security method and device

1 is a block diagram showing a security device for data protection of a microcomputer of the present invention.

2A, 2B, 2C, and 2D show timing charts for the signals of FIG.

The present invention relates to a security method and apparatus for a microcomputer, and more particularly, to a security method and apparatus for data protection of a microcomputer.

Microcomputers have been around for a long time, and the range of applications from word processing to engineering and scientific applications is increasing day by day.

However, a microcomputer with a built-in memory cannot read or write data to the internal memory depending on external control pins or signal conditions.

In this case, there is a possibility that the internal data is read or tampered with by another user. This is a fatal flaw, especially in situations where security is required. Therefore, the contents of the microcomputer should not be protected or unnecessarily overwritten.

Conventionally, a unique number of a microcomputer is designated so that read and write operations can be performed only when it is satisfied.

However, when the number of digits of the unique number is substituted, the security device of the system is easily released.

Accordingly, an object of the present invention is to provide a microcomputer data security method that further enhances microdata security by adding a time variable to a unique number system.

It is another object of the present invention to provide a microcomputer security device that further enhances data security of a microcomputer by adding a variable called unique time to a system of unique numbers used in the existing.

In order to achieve the above object, the present invention provides a security device for protecting data stored in a memory in a microcomputer system,

A clock counter unit for counting a system clock when the microcomputer system is reset;

A clock comparing unit which compares the counted value of the clock counter unit with a value unique to the microcomputer system and outputs a synchronous clock if it matches;

A key code portion having unique key data for accessing a memory in the microcomputer;

A clock code unit in which an inherent time for identifying key data of the key code unit is coded based on the number of synchronous clocks generated by the clock comparing unit;

A key data buffer for storing key data externally input by a user to release the security device of the microcomputer;

And a key code detector for reading and writing the microcomputer memory when the key data stored in the data buffer and the key data of the top key code unit are compared and matched at a predetermined second synchronous clock corresponding to the code value of the clock code unit. It is a security device of a microcomputer.

In order to achieve the above another object, the present invention provides a method for protecting data of a microcomputer system,

A clock comparison step of comparing the counted value of the clock of the microcomputer system with an inherent value of the microcomputer system and outputting a synchronous clock if it matches;

When the number of occurrence of the synchronous clock in the clock comparing step and the unique time value for identifying the key data for accessing the memory of the microcomputer coincide with each other, the data inputted for external memory access and the unique key data are compared. Comparing step;

And a key code detection step that permits reading and writing of the microcomputer memory if the external key and the unique key for accessing the memory of the microcomputer match data.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an apparatus for data protection of a microcomputer of the present invention.

1 is a clock counter 112 for counting a clock by inputting a clock signal 110 and a reset signal 115, a prescaler 114 to which a system unique number is input, and the clock. Accesses a clock comparator 116 that compares the counter 112 and the prescaler 114 to output a SYNC CLOCK signal 117, a data buffer 118 that temporarily stores data 119, and a memory A key code 120 comprising key code 1 121 and key code 2 122, which are unique key data, a clock code 140 encoding a unique time for identifying the key data, and the data buffer ( A key that detects a key code by inputting the data of 118, the synchronous clock 117, the key code 120, and the clock code 140, and outputs a write protect bit 150 and a read protect bit 160. It consists of a code detector 130.

In Figure 1 the microcomputer system performs a system reset to have a state of initialization. The reset signal 115 is low active for this purpose. As soon as the initialization is completed, the clock counter 112 counts the input clock (CLOCK) signal 110.

The value counted by the clock counter 112 is compared by the clock comparator 116 with the prescaler 114 which is determined to be a system-specific value for the security of the micro system. If the compared values match, the clock comparator 116 outputs a SYNC CLOCK signal 117.

In the clock code 140, a unique time for checking key data is written in units of the number of SYNC clocks. The SYNC CLOCK signal 117 is also output to the outside of the microcomputer to be used as a synchronization signal with the outside.

The data buffer 118 stores externally input data 119 to release the security device. The key code 120 has unique key data that can access the memory in the microcomputer.

Therefore, the key code detector 130 compares the key data of the data buffer 118 with the key data of the key code 120 at the n th sync clock SYNC CLOCK corresponding to the clock code 140 value n. If there is a match, it releases the protection limiting the read and write operations.

When the data value in the data buffer 118 and the key code 120 coincide with each other, the values of the write protect bit 150 and the read protect bit 160 are toggled.

When the write protect bit 150 is released, the user can write data to the built-in memory. When the read protect bit 160 is released, the programmed data can be read.

The opportunity to release the security device here can only be one time after the system performs a reset. And the values of key code 2 122 in key code 120 must continue to be unique even if the microcomputer system is initialized by a reset.

2A, 2B, 2C, and 2D show timing charts for the signals of FIG.

FIG. 2A is a timing diagram of the reset signal 115 of FIG. 1, FIG. 2B is a timing diagram of the clock signal 110 of FIG. 1, and FIG. 2C is a timing diagram of the synchronous clock signal 117 of FIG. 2D is a timing diagram of the data (data 1, data 2) signal 119 of FIG.

When the RESET signal of FIG. 2A is LOW, the clock counter 112 of FIG. 1 does not operate, and the clock counter starts from a state where the RESET signal of FIG. 112 performs counting.

When the value counted by the clock counter 112 is equal to the value of the prescaler 114 of FIG. 1, the one-shot pulse (0, n, n + 1, n + 2, n + 3).

When the number of occurrences of the synchronous clock of FIG. 2C coincides with the value n determined by the clock code 140 of FIG. 1, the data of FIG. 2D and the key code 1 121 of FIG. Compare keycode 2 (120).

The more the number of bits of the clock code 140 and the number of key codes 120 for microcomputer data access, which is the intrinsic time of verifying the key data and the prescaler 114 having the unique number of the system of FIG. The likelihood of becoming further reduced.

As described above, according to the present invention, data security of a microcomputer system can be enhanced by allowing a key code that can access the memory of the microcomputer to be detected only at a specific time.

Claims (4)

A security device for protecting data stored in a memory in a microcomputer system, comprising: a clock counter unit for counting a system clock when the microcomputer system is reset; A clock comparing unit which compares the counted value of the clock counter unit with a value unique to the microcomputer system and outputs a synchronous clock if it matches; A key code portion having unique key data for accessing a memory in the microcomputer; A clock code unit in which an inherent time for identifying key data of the key code unit is coded based on the number of synchronous clocks generated by the clock comparing unit; A key data buffer for storing key data externally input by a user to release the security device of the microcomputer; And a key code detection unit for reading and writing the microcomputer memory when key data stored in the data buffer and key data of the key code unit are compared and matched at a predetermined second synchronous clock corresponding to a code value of the clock code unit. Security device of a microcomputer, characterized in that. The security apparatus of claim 1, wherein the clock comparator generates a synchronous clock by one shot pulse by a half cycle of a click. 2. The security apparatus of claim 1, wherein the key code portion and the clock code portion continue to maintain unique values of key code and click code values even when the micro computer system is initialized by a reset. CLAIMS 1. A method for protecting data in a microcomputer system, comprising: a clock comparing step of comparing a counted value of a clock of the microcomputer system with an intrinsic value of the microcomputer system and outputting a synchronous clock when the microcomputer system matches and compares a unique value of the clock; When the number of occurrence of the synchronous clock in the clock comparing step and the unique time value for identifying the key data for accessing the memory of the microcomputer coincide with each other, the data inputted for external memory access and the unique key data are compared. Comparing step; And a key code detection step that allows reading and writing of the microcomputer memory if the data of the data comparison step coincides with the unique key for accessing the memory of the microcomputer.