JPH10164028A - Data communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high safety for wire tapping by permitting a transmission side to divide original data into plural pieces of data and to transmit them through the use of plural communication lines and permitting a reception side to synthesize data received from plural communication lines in a procedure opposite to a method for dividing data received from the plural communication lines and to restore original data. SOLUTION: A CPU 101 executes communication in accordance with a program stored in a memory 103. At the time of transmitting data, data stored in the memory 103 or an external storage device 108 is divided into two and they are transferred to a first communication equipment 104 and a second communication equipment 106 through a system bus 102. The communication equipments 104 and 106 convert received data into respective communication signals and output them to a first communication line 105 and a second communication line 107. At the time of receiving data, the CPU reads the rule array R of division/synthesis into the memory 103, writes data D1 received from the first communication equipment 104 into the memory 103 and writes data D2 received from the second communication equipment 106 into the memory 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a communication method for transmitting and receiving data using a plurality of communication paths.

[0002]

2. Description of the Related Art Conventionally, there is data encryption as a method for protecting data exchanged by a method that can be received at a destination other than a data transmission destination such as a cellular phone. In order to prevent unauthorized recipients from easily decrypting by encryption, the complexity of the encryption method must be increased. However, as the complexity of the encryption method increases, so does the time required to encrypt and subsequently decrypt the data. Thus, there is a need for an encryption method that is difficult for unauthorized recipients to decrypt and that results in encrypted data that has relatively short encryption and decryption times. As an example of this, there is a method described in JP-A-7-281596. This is a method for encrypting data consisting of a plurality of data segments into a plurality of encrypted data blocks and associated control blocks. This method
The cipher used to encrypt each data segment to form an encrypted data segment, create an encrypted data block containing the encrypted data segment, and encrypt the data into the encrypted data block Create a control block having encryption information such as an encryption function. Thus, the effectiveness of the encryption method is increasing while maintaining a short encryption time.

[0003]

Recently, devices that perform wireless communication at home, such as cordless telephones, have become widespread. For this reason, the danger of eavesdropping on data communication and telephone calls in the home is increasing. As a method of protecting the communication data and the contents of the call, there is the above-mentioned encryption. However, when communication is performed using radio waves or the like, encryption cannot prevent reception by anyone other than the sender, and may be decrypted. Therefore, there is a need for a communication method in which it is difficult for a person other than the transmission destination to receive all the transmission data.

An object of the present invention is to provide a data communication method that is highly secure against eavesdropping.

[0005]

In order to solve the above-mentioned problems, according to a data communication method of the present invention, a transmitting side divides original data into a plurality of data and transmits them by using a plurality of communication paths. I do. Then, the receiving side restores the original data by combining the data received from the plurality of communication paths in a procedure reverse to the division method.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a data communication method according to the present invention will be described below.

Hereinafter, a first embodiment of the present invention will be briefly described with reference to FIGS.

FIG. 1 is a simplified block diagram of the hardware configuration of a communication apparatus according to the present embodiment, FIG. 2 is a memory map for data transmission, FIG. 3 is a memory map for data reception, and FIG.
FIG. 5 is an example of an array R representing rules of division and composition, FIG. 5 is a flowchart of data division, and FIG. 6 is a flowchart of data composition.

In FIG. 1, 101 is a CPU, 102 is a system bus for transmitting control commands and data, 103 is a memory for storing control commands and data, 104 is a first communication device, and 105 is a first communication device 104 for communication. , A second communication device 107, a second communication channel with which the second communication device 106 communicates, and an external storage device 108 such as a hard disk.

The CPU 101 performs communication according to a program stored in the memory 103. At the time of data transmission, the data stored in the memory 103 or the external storage device 108 is divided into two, and the two data are transferred to the first communication device 104 and the second communication device 106 respectively by the system bus 1.
Pass through 02. Each of the devices 104 and 106 converts the passed data into a respective communication signal, and
5. Output to the second communication path 107.

FIG. 2 shows a part of a memory map of the memory 103 at the time of data transmission.

R is an array area representing rules for performing division and synthesis, D is a transmission data area, D1 is a data area for dividing transmission data D in accordance with the array R and storing data transmitted from the first communication device 104 , D2 are data areas for storing the data to be transmitted from the second communication device 106 by dividing the transmission data D in accordance with the array R.

FIG. 3 shows a part of a memory map of the memory 103 at the time of data reception.

R is an array area representing rules for performing division and synthesis, D1 'is a data area for storing data received by the first communication device 104, and D2' is a data area for storing data received by the second communication device 106. A data area D ′ is a data area for storing data obtained by combining the received data D1 ′ and D2 ′ according to the array R.

FIG. 4 shows an example of the divided composite array R. Array R
Stores rules for dividing and combining data. FIG. 4 shows rules for dividing and combining data in units of 8 bits.

The numbers in the upper row of the figure indicate the element numbers of the array R. The boxes below it represent the elements of array R. The content of each element indicates a communication device and a communication path for transmitting and receiving data corresponding to the element. 1 indicates the first communication device 104 and the first communication channel 105, and 2 indicates the second communication device 106 and the second communication channel 107.

At the time of data transmission, data is divided according to the rule of division and synthesis, and at the time of data reception, data is restored according to this rule.

FIG. 5 is a flowchart of data division at the time of data transmission.

I, j, k, l are positive integers, D_i, D1_
j, D2_k, R_l represent the i-th bit of the transmission data D, the j-th bit of the divided transmission data D1, the k-th bit of the divided transmission data D2, and the first element of the array R of the division combination rule.
The left arrow represents a right-to-left assignment, and mod represents the remainder of dividing the left number by the right number. “i”, “j” and “k” indicate the bits of the transmission data D and the divided transmission data D1 and D2, respectively, and “1” indicates the element of the rule array of the divisional synthesis that is focused on.

FIG. 6 is a flowchart of data synthesis at the time of data reception.

D'_i, D1'_j, D2'_k are the i-th bit of the received data D ', the j-th bit of the divided received data D1',
Represents the k-th bit of the divided reception data D2 '.

I, j, and k indicate the bits of the received data D 'and the divided received data D1' and D2 ', respectively, and 1 indicates the element of the rule array R of the divided synthesis. Indicates whether you are doing.

A data division method when data is transmitted by the apparatus shown in FIG. 1 will be described with reference to FIGS. 2, 4 and 5.

The CPU 101 performs data transmission according to a program stored in the memory 103. At the time of data transmission, first, the CPU 101 reads the transmission data D and the rule array R of division and synthesis into the memory 103 as shown in FIG. next,
The read transmission data D is divided according to the flowchart shown in FIG.

As an example, let us consider a case where 10-bit data of D = 1001011010 is divided and transmitted according to the rule arrangement R of division and synthesis shown in FIG. i = 1, j =
When 1, k = 1, l = 1, R_1 is 2, so that D_1 is substituted into D2_1, D2_1 = 1, and k, i, l are updated, and i = 2, j = 1, k = 2. 1 = 2. next,
Since R_2 is 1, D_2 is substituted into D1_1 and D1_1 =
It becomes 0. In the same manner, the operation is repeated until i becomes the data length 10, and the processing is terminated. At this time, D1 = 00010 and D2 = 1
1101.

Thereafter, the CPU 101 sets the first communication device 1
04 causes D1 of the memory 103 to be output to the first communication path 105. Also, the D2 of the memory 103 is stored in the second communication device 106.
To the second travel path 107.

Since the data D1 and D2 divided in this way lack data from the transmission data D, the individual divided transmission data D1 and D1 transmitted from the communication devices 1 and 2 respectively.
The transmission data D cannot be composed from D2.

A data synthesizing method when data is received by the apparatus shown in FIG. 1 will be described with reference to FIGS. 3, 4, and 6.

The CPU 101 receives data according to a program stored in the memory 103. At the time of data reception, first, the CPU 101 reads the rule array R of division and synthesis into the memory 103 as shown in FIG.
Data D1 ′ received from the second communication device 106 is written into the memory 103, and data D2 ′ received from the second communication device 106 is written into the memory 103.

Next, the written divided reception data D
1 'and D2' are synthesized according to the flowchart shown in FIG.

As an example, D1 '= 00010, D2' = 11
Consider a case where two 5-bit data 101 are received and combined according to the rule arrangement R of the divisional combination shown in FIG.

The total length of the received data is 10 bits, and the length of the received data D 'is 10 bits. Further, i = 1,
When j = 1, k = 1, l = 1, R_1 is 2, so that D ′
_1, D2′_1 is substituted, D′ _1 = 1, and k, i,
1 is updated, and i = 2, j = 1, k = 2, and l = 2. Next, since R_2 is 1, D1′_1 is substituted for D′ _2, and D′ _2 = 0. Similarly, i has a data length of 10
The same operation as described above is performed until the operation is completed, and the process ends. At this time, D ′ = 1010101010.

As described above, when the rule of division synthesis is used, the original data transmitted from the division reception data D1 'and D2' is converted to D '.
Can be stored.

By performing transmission and reception as described above, data can be transferred using two communication paths.

As shown in the example of FIG. 4, when the applicable data length of the rule of the divisional synthesis is 8 bits, there are 2 @ 8 powers of the rule of the divisional synthesis. Here, assuming that the application data length of the rule of the divisional synthesis is m bits, the number of elements of the rule array R of the divisional synthesis is m, and the rule of the divisional synthesis that can be created is 2 m. m
Is larger, the number of split composition rules increases,
It is difficult to find the rules of division and composition.

Further, assuming that the number of communication paths to be used is n and the data is divided into n pieces for transmission and reception, each element of the array of division and composition rules takes n types of values from 1 to n. Thus, the number of rules of the divisional synthesis can be made to be n to the m-th power.

In other words, the larger the number n of communication paths to be used, the greater the number of rules of division and synthesis that can be made, and the more difficult it is to find the rule of division and synthesis.

If all the divided data is not received, the data will be missing from the original data. Therefore, if a communication path having directivity and not easily received by an external device, such as a communication path using infrared rays, is used, even one of the communication used increases the security of the entire transmission data. The communication path using infrared rays has high security due to directivity, but has a low communication speed. However, if at least one of the n communication paths uses a communication path with a high communication speed, the original data is divided into data having a size proportional to the speed of the communication path, and the divided data is assigned to the communication path. The communication speed as a whole can be increased. In this way, a secure and fast communication can be performed by combining a highly secure communication path and a fast communication speed communication path.

[0039]

According to the present invention, since the divided individual data lacks the original data, the original data cannot be formed even if the individual data is received.

Even if all data are received, assuming that the data length to which the rule of division and composition is applied is m and the number of divisions of the data is n, the number of division and composition methods is m to the nth power. When m is large, the number becomes very large, and it is difficult to find a division method.

As described above, the communication method of the present invention can enhance the security of communication.

[Brief description of the drawings]

FIG. 1 is a block diagram of a hardware configuration of a communication device according to an embodiment.

FIG. 2 is an explanatory diagram of a memory map at the time of data transmission.

FIG. 3 is an explanatory diagram of a memory map at the time of data reception.

FIG. 4 is an explanatory diagram of an array R representing rules of division and composition.

FIG. 5 is a flowchart of data division.

FIG. 6 is a flowchart of data synthesis.

[Explanation of symbols]

 101: CPU, 102: System bus, 103: Memory, 104: First communication device, 105: First communication channel, 106: Second communication device, 107: Second communication channel, 108: External storage device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makiko Ikeda 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi Systems Development Laboratory (72) Inventor Satoshi Onuma 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Stock Company Hitachi Image Information System (72) Inventor Toru Owada 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture

Claims (3)

[Claims] In a communication method using a plurality of communication devices and communication paths, a data block to be transmitted is divided into a plurality of data blocks, and data is transmitted using some of the communication devices and communication paths. Data communication method. 2. A communication method using a plurality of communication devices and communication paths, receiving data divided into data blocks from some of the plurality of communication paths, and converting original data from the data blocks. A data communication method characterized by restoring. 3. The method according to claim 1, wherein data division is performed.
Restoration is a data communication method that follows specific rules, which are expressed as arrays.