JPH04347948A - Secret communication equipment - Google Patents

Abstract

PURPOSE:To inhibit the use of a device unless following the determined procedures and to prevent the access to ciphering algorithm, rule, or the like by not driving the device in the case of an improper comparison result of a comparator. CONSTITUTION:When a number is inputted from a keyboard switch 1, the input number is recorded in a first memory 2. The input number is displayed on a display device 3, and a set number preliminarily recorded and set in a second memory 4 and the number in the first memory 2 are read and are compared with each other by a comparator 5 to discriminate whether they coincide with each other or not. The comparison result is stored in a third memory 6; and if the result in the third memory 6 is proper (both numbers coincide with each other), a circuit part 8 is so driven that a secret communication equipment can perform transmission and reception. If the input number and the set number do not coincide with each other, the circuit part 8 is not driven to inhibit the use of the secret communication equipment.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a communication device having a secret function for encrypting and transmitting voice and digital information, and in particular, it allows only persons qualified for communication to use the communication device, and furthermore, it The present invention relates to a secret communication device that can prevent algorithms, rules, etc. from being leaked to third parties.

0002

2. Description of the Related Art Hitherto, communication devices with a secret function (secure communication devices) have been used to prevent communication contents from being leaked to third parties through wireless communication or public communication lines. This conventional secret communication device will be explained using the schematic diagram of FIG.

[0003] In the conventional secure communication device, in the case of the secure communication device 21 on the transmitting side, voice input is performed, the voice is digitized, and the digitized voice is further set in the secure communication device 21 on the transmitting side. Encryption is performed according to the encryption rules, and the secret communication device 2 on the receiving side uses the communication line 23.
2. Furthermore, in the secure communication device 22 on the receiving side, rules for decrypting codes are set so as to correspond to the encryption rules of the secure communication device 21 on the sending side. After receiving encoded data and decrypting the code, it converts the audio data into analog and outputs audio.

[0004] In such a conventional secret communication device,
A third party connects the communication line 24 in the middle of the communication line 23,
Even if an attempt was made to eavesdrop by installing the receiving device 25, the communication data was encrypted, making it impossible to eavesdrop by outputting it as audio.

[0005]

[Problems to be Solved by the Invention] However, with the above-mentioned conventional secret communication device, if the secret communication device falls into the hands of a third party who is not qualified to communicate due to some trouble, or if the secret communication device There is a problem in that if a person who is not qualified to communicate illegally infiltrates a place where a device is installed, the person who is not qualified to communicate will use the device and learn the contents of the communication.

[0006] In addition, in the above-mentioned conventional secret communication device, if the secret communication device falls into the hands of a third party due to some trouble, the encryption method, random number generation algorithm and rules for encryption There is a risk that information such as the above may be decoded, and there is a problem that the confidential communication device may be intercepted.

Furthermore, even if the secure communication device does not fall into the hands of a third party, a third party can access the memory in which information such as encryption rules is recorded without permission, and the encryption There was a problem that the protection of encrypted information was not perfect, as there was a risk that information such as the rules of the system could be changed or information such as the rules of encryption could be destroyed.

The present invention was made in view of the above-mentioned circumstances, and it is impossible to use a secure communication device even if an attempt is made to use it without following a predetermined procedure, and the encryption rules set inside the device cannot be used. An object of the present invention is to provide a secure communication device that cannot read or write data without following proper procedures.

[0009]

Means for Solving the Problems The invention according to claim 1 for solving the problems of the conventional example provides a secure communication device including a keyboard switch for inputting an input number, and a keyboard switch for inputting the input number. a second memory for recording a preset setting number; a comparator for comparing the input number in the first memory with the setting number in the second memory; The apparatus is characterized by comprising a third memory for recording comparison results in the third memory, and a circuit section that does not drive the apparatus when the comparison results recorded in the third memory are inappropriate.

[0010] The invention according to claim 2 for solving the problems of the prior art is, in a secret communication device, comprising: a keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording the input setting number in the first memory, a comparator for comparing the input number in the first memory and the setting number in the second memory, and recording a comparison result in the comparator. and a circuit section that prohibits transmission and reception when the comparison result recorded in the third memory is inappropriate.

[0011] The invention according to claim 3 for solving the problems of the prior art is, in a secret communication device, comprising: a keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording the input setting number in the first memory; a comparator for comparing the input number in the first memory with the setting number in the second memory; a third memory for recording a comparison result of the setting numbers; a fourth memory for storing encryption information; and a third memory for storing encryption information; and a circuit section that prohibits access to the fourth memory when accessing the fourth memory.

[0012] The invention according to claim 4 for solving the problems of the prior art is, in a secret communication device, comprising: a keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording the input setting number in the first memory; a comparator for comparing the input number in the first memory with the setting number in the second memory; a third memory for recording a comparison result of the setting numbers; a fourth memory for storing encryption information; and a third memory for storing encryption information; The device is characterized by having a circuit section that is not driven when the device accesses the device.

[0013] The invention as set forth in claim 5 for solving the problems of the conventional example provides a secure communication device as set forth in claim 1, claim 2, claim 3, or claim 4, in which input numbers and The present invention is characterized in that a microcomputer processing section including a program memory is provided in place of a comparator that performs the operation of comparison with a set number.

[0014]

According to the first aspect of the invention, in the secure communication device, the input number from the keyboard switch and the setting number set in the second memory are compared by the comparator,
If the comparison result is inappropriate, the circuit section does not drive the secure communication device, so a third party who does not follow the prescribed procedure cannot use the device.

According to the second aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
The setting number set in the memory of the device is compared with the setting number set in the memory of A third party who does not follow the procedures will not be able to send or receive data using the device.

According to the third aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
A comparator compares the setting number set in the memory of Therefore, a third party who does not follow established procedures cannot access the encrypted information on the device.

According to the fourth aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
A comparator compares the setting number set in the memory of the device, and if the comparison result is inappropriate and an attempt is made to access the fourth memory where the encryption information is recorded, a secret communication that does not activate the device occurs. Since it is a device, a third party who does not follow the established procedures cannot use the device.

According to the invention set forth in claim 5, since the confidential communication device according to claim 1, 2, 3, or 4 is configured such that the operation of the comparator is performed by a processing section of a microcomputer including a program memory, A third party who does not follow the specified procedures will not be able to access the encrypted information on the device or use the device.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a secure communication device according to an embodiment of the present invention.

The secure communication device of this embodiment includes a keyboard switch (SW) 1 and a keyboard switch (SW)
The first memory (MEM) records the numbers input from 1
1) 2, a display (DISP) 3 that displays the input number, and a second memory (C) that records the number held by the device.
ODE) 4 and a comparator (COMP) 5 that checks the numbers.
, a third memory (MEM3) 6 that records the comparison results, a circuit unit (COM) 8 that normally drives the device based on the comparison results in the third memory (MEM3) 6, and encryption algorithms and rules. A fourth memory (M
It is composed of EM4)7. Then, the circuit section (C
OM) 8 is connected to input and output for transmission and reception.

Next, each component of the secure communication device of this embodiment will be specifically explained. keyboard switch (SW
) 1 is composed of, for example, 10 push button switches corresponding to numbers 0 to 9 and function keys for controlling operations. This keyboard switch (SW) 1
may also serve as an input switch for rules, etc. for cryptographic processing.

The first memory (MEM1) 2 is a memory that stores numbers input by operating the keyboard switch (SW) 1. Display (DISP)
) 3 is a display device that displays the input number input from the keyboard switch (SW) 1, and a fourth memory (MEM 4
) 7 can also be displayed. The second memory (CODE) 4 is a memory in which the numbers necessary for using the secret communication device are recorded in advance, and may be fixed to a device-specific number by wiring, or can be rewritten by a ROM etc. Good too.

The comparator (COMP) 5 has a first memory (
The number recorded in MEM1)2 and the second memory (COD
E) The number recorded in 4 is read and compared, and the validity of the input number is determined. In addition, the comparator (
COMP) 5 can be configured by a logic circuit or can be realized by a microcomputer program.

The third memory (MEM3) 6 includes a comparator (
This is a memory for recording the results of comparison and verification in COMP) 5. And the fourth memory (MEM4) 7
stores encryption information such as algorithms and rules for encrypting digitized audio data.

The circuit section (COM) 8 includes a comparator (COMP
) 5 is a circuit that operates the device normally according to the judgment result. For example, if the judgment comparison result is inappropriate, it turns off the power, and also controls the circuit section (COM) 8 for transmitting and receiving communication equipment. The transmitting and receiving transmission lines can be disconnected by a relay or the like if the comparison result is inappropriate.

Next, in the secure communication device of this embodiment,
Describes how to prohibit use of the device by third parties who are not qualified to communicate.

When a number is input from the keyboard switch (SW) 1, the input number is recorded in the first memory (MEM1) 2, the input number is displayed on the display (DISP) 3, and the comparator (COMP) 5 reads the setting number recorded in advance in the second memory (CODE) 4 and the number in the first memory (MEM 1) 2, and determines whether both numbers match; The result is stored in the third memory (MEM3) 6, and if the result in the third memory (MEM3) 6 is correct (when both numbers match), the circuit unit (COM) 8 is driven. and put the secure communication device in a state where it can send and receive data.

Further, if the input number and the setting number do not match, the circuit section (COM) 8 is not driven, making the secret communication device unusable. Further, as shown in FIG. 1, a circuit section (COM) 8 is provided on the transmission path for transmitting and receiving,
If the input number and the set number do not match, it is also possible to disable transmission and reception by disconnecting the transmission path using a relay or the like. The input number is preferably a number that cannot be easily found by a third party and has a number of digits that the operator can remember.

According to this embodiment, the keyboard switch (
Input number from SW) 1 and second memory (CODE) 4
The circuit unit (COM) 8 operates normally to enable the device to be used only when the setting number recorded and set in advance matches, or the circuit unit (COM) 8 secures the transmission path for transmission and reception. Because it is a communication device, if the device is installed in a vehicle or used in a room where third parties frequently come and go, the device may be used by a third party who is not qualified to communicate, and the content of the communication may be lost. This has the effect of preventing the leakage of information and the intrusion of unauthorized information.

Furthermore, in the secure communication device of the above embodiment, the input number does not match the setting number of the second memory (CODE) 4, and the fourth memory (CODE) in which the encryption algorithm, rules, etc. are stored. A secure communication device that protects the encryption algorithm, rules, etc. set in the device when reading and writing access is made to MEM4) 7 will be explained using FIG. 1.

[0031] The fourth memory (MEM4) 7 in which encryption algorithms, rules, etc. are stored includes a circuit section (COM
)8 is connected, and the fourth memory (M
It is possible to write and read encrypted information in EM4)7.

However, the fourth memory (MEM4) 7 can be accessed only when the circuit section (COM) 8 is operating normally, that is, the input number from the keyboard switch (SW) 1 is Only when the setting number matches the setting number in the memory (CODE) 4, the circuit unit (COM) 8 is driven normally and the fourth memory (MEM4) 7 can be accessed.

Next, a method for protecting internal encryption algorithms, rules, etc. in the secure communication device of the embodiment shown in FIG. 1 will be explained. Keyboard switch (SW) 1
When the comparator (COMP) 5 determines whether the number input from
M3) 6 and the result is given to the circuit section (COM) 8. If the fourth memory (MEM4) 7 is accessed after the input number and the setting number of the second memory (CODE) 4 match, the fourth memory The contents of memory (MEM4) 7 (
Encryption algorithms, rules, etc.) can be read and written.

However, if the number is not input or if an incorrect number is input and the fourth memory (MEM4) 7 is accessed, the circuit section (COM) 8 does not operate normally and the fourth memory (MEM4) 7 is accessed. The fourth memory (MEM4) 7 is operated to stop its function so that the memory (MEM4) 7 cannot be accessed. It is also possible to make the communication device unusable because the circuit unit (COM) 8 does not operate normally.

FIG. 2 is a circuit configuration block diagram showing another embodiment that performs the same operation as FIG. 1. Next, a secure communication device according to another embodiment will be explained.

In the secure communication device of this other embodiment, the operation of the comparator (COMP) 5 of FIG. 1 is realized by a program of a microcomputer (processing section) having a program memory. In this other embodiment, the functions of the circuit described above are executed by one microcomputer through time-sharing processing. The processing unit (CPU) 9 of the microcomputer in FIG. 2 includes a program memory, and each memory (MEM1, CODE, MEM3, MEM4)
) and performs number verification and other control processing.

[0037] By inputting the proper input number, the circuit section (C
OM) 8 without driving the fourth memory (MEM)
4) According to the secure communication device of this embodiment in the case where access is made to the fourth memory (MEM4) 7, the circuit section (COM) 8 makes the device unusable or the secure communication prohibits access to the fourth memory (MEM4) 7. Since it is a device, it is possible to prevent the encryption algorithm, rules, etc. stored in the fourth memory (MEM 4) 7 in the secure communication device from being leaked to a third party.

[0038]

According to the invention set forth in claim 1, in the secure communication device, the input number from the keyboard switch and the setting number set in the second memory are compared by the comparator, and the comparison result is If it is inappropriate, the circuit section will not operate the confidential communication device, so a third party who does not follow the established procedures will not be able to use the device, thus preventing unauthorized use by a third party. There is an effect that can be done.

According to the second aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
The setting number set in the memory of the device is compared with the setting number set in the memory of A third party who does not follow the procedure will not be able to send or receive data using the device, which has the effect of preventing unauthorized communication by a third party.

According to the third aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
A comparator compares the setting number set in the memory of Therefore, a third party who does not follow the prescribed procedures cannot access the encrypted information of the device, which has the effect of protecting the encrypted information.

According to the fourth aspect of the invention, in the secure communication device, the input number from the keyboard switch and the second
A comparator compares the setting number set in the memory of the device, and if the comparison result is inappropriate and an attempt is made to access the fourth memory where the encryption information is recorded, a secret communication that does not activate the device occurs. Since the device is used as a device, a third party who does not follow the prescribed procedures cannot use the device, which has the effect of preventing unauthorized use by a third party.

According to the invention set forth in claim 5, since the confidential communication device according to claim 1, 2, 3, or 4 is configured such that the operation of the comparator is performed by a processing section of a microcomputer including a program memory, Third parties who do not follow these procedures will not be able to access or use the encrypted information on the device, and will be unable to protect the encrypted information and prevent unauthorized use by third parties. There is an effect that can be done.

[Brief explanation of drawings]

FIG. 1 is a partial circuit block diagram of a secure communication device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a partial control processing circuit of a secure communication device according to another embodiment.

FIG. 3 is a conceptual diagram of a conventional secret communication device.

[Explanation of symbols]

1 Keyboard switch (SW) 2 First memory (MEM1) 3 Display (DISP) 4 Second memory (CODE) 5 Comparator (COMP) 6 Third memory (MEM3) 7 Fourth memory (MEM4) 8 Circuit section (COM) 9 Processing unit (CPU) 21 Transmitter side secret communication device 22 Receiving side secret communication device 23 Communication line 24 Communication line 25 Receiving device

Claims (5)

[Claims] 1. A keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording a preset setting number;
a comparator for comparing the input number in the memory with the setting number in the second memory; a third memory for recording the comparison result in the comparator; A secure communication device comprising: a circuit section in which the device does not operate when the comparison result is inappropriate. 2. A keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording a preset setting number;
a comparator for comparing the input number in the memory with the setting number in the second memory; a third memory for recording the comparison result in the comparator; and a circuit section that prohibits transmission and reception when the comparison result is inappropriate. 3. A keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording a preset setting number;
a comparator for comparing the input number in the memory and the setting number in the second memory; a third memory for recording a comparison result of the input number and the setting number in the comparator; a fourth memory that stores information on the comparison, and a circuit that prohibits access to the fourth memory when the fourth memory is accessed when the comparison result in the third memory is inappropriate. A secret communication device characterized by having a section. 4. A keyboard switch for inputting an input number; a first memory for recording the input number; a second memory for recording a preset setting number;
a comparator for comparing the input number in the memory and the setting number in the second memory; a third memory for recording a comparison result of the input number and the setting number in the comparator; and a circuit section that is not driven by the device when accessing the fourth memory when the comparison result in the third memory is inappropriate. A secret communication device. 5. Claim 1, characterized in that a processing section of a microcomputer including a program memory is provided in place of the comparator that performs the operation of comparing the input number and the setting number.
The secret communication device according to the description or claim 2 or claim 3 or claim 4.