JPH09114373A - Encoding system, decoding system and data processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an encoding system which use an encoding conversion table to be referred to when the encoding data are encoded with a small scale, and a which use a system which use a decoding conversion table to be referred to when the encoded data are decoded with a small scale. SOLUTION: The encoding is performed by providing one encoding conversion table 153, and so as to make the address of the encoding conversion table 153 equal to an encoding key number a start address when referring to the encoding conversion table 153, and make a numerical value stored in an address behind by the numerical value expressing the data encoded from the start point address of the encoding conversion table 153 the encoding data. Further the decoding is performed by providing one decoding conversion table replacing the addresses of the encoding conversion table 153 with the stored numerical values, and performs so as to read out the numerical value stored in the address behind by the numerical value expressing the encoding data from a head address of the decoding conversion table, and make the result subtracting the encoding key number from the read out numerical value the decoding data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encryption system and a decryption system, and more particularly, to an encryption change table referred to when encrypting data to be encrypted (data to be encrypted), and an encrypted change table. The present invention relates to an encryption method and a decryption method that require a small-scale decryption conversion table to be referred when decrypting existing data (encrypted data).

Data processing was carried out by a stand-alone computer in its early days, but in recent years, data transmission network (for example, LAN) in a premises, or between remote places using a public communication network or a dedicated network has been used. It has come to be performed while communicating between computers via a data transmission network. This must have been achieved by technological advances in hardware and software, but it is a result of the realization of widespread economic activities in real time and widespread realization.

As described above, in the case of performing data communication by performing data communication via a communication line regardless of the distance between terminals, it is extremely important to protect the confidentiality of the data on the communication line and in the shared memory. Data security technologies include technology that scrambles transmitted data with a pseudo-random code and technology that limits reading and writing to memory to a specific person. Once the ID number given to the authorized person is known, confidentiality cannot be secured. Therefore, recently, a technique of encrypting transmission data is widely used.

On the other hand, in the field of electronic computers, downsizing has become a trend in the world, and as a hardware, a workstation or a personal computer is used to accelerate data processing. Although the processing capacity and storage capacity of today's workstations and personal computers are increasing, the need for data processing capacity exceeds them. Therefore,
There is a strong demand for implementation of an encryption method and a decryption method that require only a small scale of hardware and software for high security protection.

[0005]

2. Description of the Related Art FIG. 23 shows a configuration of a data processing apparatus to which a conventional encryption system is applied, and shows a configuration directly related to the encryption system, taking a form of a client & server system as an example.

In FIG. 23, 1d is a client,
11 is a keyboard, 12 is a display device, and 13 is input / output (I
/ O) controller, 14 is a central controller (CPU), 15
d is a random access memory (RAM). On the random access memory, the encrypted data buffer 151 for storing the data to be encrypted, the encryption processing program 152b, the encryption conversion table 153a referred to when the encryption processing program encrypts, the encryption Areas of an encrypted data buffer 154 for storing the encrypted data and an encryption key number buffer 155 for storing the encryption key number used at the time of encryption are secured. Reference numeral 2 is a server, 21 is an input / output (I / O) control device, and 22 is a magnetic disk memory, for example. An area of an encrypted data file 221 for receiving and storing data encrypted by the client and an encryption key number file 222 for storing the encryption key number used when the client encrypts the data on the magnetic disk memory. Is secured.

The encrypted data input from the keyboard is temporarily stored in the encrypted data buffer. The encryption processing program determines the encryption key number using, for example, a random number table, selects the encryption conversion table corresponding to the determined encryption key number, and refers to the selected encryption conversion table to determine the basic data The encrypted data is encrypted for each unit and stored in the encrypted data file. The encryption key number is stored in the encryption key number buffer. And
When the encryption of all the data to be encrypted is completed, the contents of the encrypted data file and the contents of the encryption key number buffer are transmitted to the server via the input / output control device 13. The central control unit of the server (not shown) stores the encrypted data received via the input / output control unit 21 in the encrypted data file in the magnetic disk memory, and similarly uses the received encryption key number as the encryption key. Store in number file.

The encryption conversion table referred to during encryption is prepared so as to correspond to all the encryption key numbers that may be determined. Although not particularly shown in the decryption, the reverse process to the above is performed to restore the encrypted original data. Decryption is performed by referring to the decryption conversion table, but the decryption conversion table is also prepared for all the encryption key numbers that may be determined.

[0009]

As described above, in the data processing device to which the conventional encryption system and decryption system are applied, the encryption conversion table and the decryption conversion table may be determined. We are preparing for all key numbers. This makes it difficult to decipher, but the area for the encryption conversion table becomes so large that it is not compatible with downsizing.

According to the present invention, in order to solve such a problem, an encryption change table referred to when encrypting encrypted data and a decryption conversion table referred to when decrypting encrypted data are small. It is an object of the present invention to provide an encryption method and a decryption method that can be completed.

[0011]

In the first encryption method according to the present invention, one encryption conversion table is provided, an encryption key number is randomly determined, and the encryption key number is converted into an encryption conversion table. This is the starting point address for reference. Then, the encrypted data input for each basic unit of data is read, and the encrypted conversion table is added to the address determined by adding the numerical value indicating the read encrypted data to the previously determined starting address. The stored contents are determined as encrypted data and stored in the encrypted data buffer.
This process is performed for all the encrypted data, and when the encryption process is completed, the encrypted data and the encryption key number are transmitted to the server.

According to the first encryption method of the present invention,
It has one encryption conversion table, and randomly changes the starting address when referring to the encryption conversion table by an encryption key number that is randomly determined. Therefore, an encryption method having a security level equivalent to having an encryption conversion table corresponding to all the encryption key numbers that may be determined even though only one encryption conversion table is provided. Can be realized.

The first decryption system of the present invention has one decryption conversion table corresponding to the encryption conversion table in the first encryption system, and for each basic unit of encrypted data received from the server. , Of the encryption conversion table,
The content of the address equal to the numerical value indicating the encrypted data is read, the encryption key number received from the server is subtracted from the read content, and the subtraction result is the decrypted data. Then, the above process is repeated for the entire encrypted data.

According to the first decoding method of the present invention,
It has one decryption conversion table, and an encryption key number determined at random is subtracted from the contents read from the decryption conversion table to obtain decrypted data. Therefore, even if only one decryption conversion table is provided, a decryption method having security equivalent to having a decryption conversion table corresponding to all the encryption key numbers that may be determined. Can be realized. It should be noted that the original data can be restored by performing decryption processing on the data encrypted by the first encryption method by the first decryption method. explain.

In the second encryption method of the present invention, one encryption conversion table is provided, and the contents of the address obtained by adding a numerical value expressing the basic unit of the encrypted data to the start address of the encryption conversion table The encrypted key number that is read out and randomly determined is subtracted from the read content, and the subtraction result is encrypted data. After the above processing is performed for all the encrypted data, the encrypted data and the encryption key number are transmitted to the server.

According to the encryption method of the present invention, one encryption conversion table is provided, and the encryption key number determined at random is subtracted from the contents read from the encryption conversion table for encryption. Since it is data, it has the same level of security as having an encryption conversion table corresponding to all the encryption key numbers that can be determined even though it only has one encryption conversion table. An encryption method can be realized.

The second decryption method of the present invention has one decryption conversion table corresponding to the encryption conversion table in the second encryption method, and refers to the decryption conversion table for the encryption key number. As the starting point address at this time, the contents of the address obtained by adding a numerical value indicating the contents of the basic unit of the encrypted data to the starting point address are read from the decoding conversion table to obtain the decrypted data. Then, the above-described processing is performed on the entire encrypted data for each basic unit of data.

According to the second decryption method of the present invention, one decryption conversion table is provided, and the decryption conversion table is referred to by using the encryption key number as the starting address of the decryption conversion table. Although only the decryption conversion table is provided, it is possible to realize security equivalent to having a decryption conversion table corresponding to all the encryption key numbers that may be determined.

The third encryption method of the present invention has one encryption conversion table and one index table for determining the starting point address when referring to the encryption conversion table. The content of the address equal to the encryption key number determined in step 1 is used as the starting point address when referring to the encryption conversion table, and the content of the basic unit of the encrypted data is displayed at the starting point address of the encryption conversion table. The contents of the address to which a numerical value has been added are read and used as encrypted data. Then, the above-mentioned encryption processing is performed on all the encrypted data, and the encrypted data and the encryption key number are transmitted to the server.

According to the third encryption method of the present invention, it has one index table and one encryption conversion table, and refers to the encryption conversion table for the contents of the address of the index table which is equal to the encryption key number. Since it is used as the starting address when doing, it realizes security equivalent to having an encryption conversion table corresponding to all the encryption key numbers that can be determined, even though it has only one encryption conversion table. can do.

The third decryption system of the present invention has one decryption conversion table corresponding to the encryption conversion table in the third encryption system, and has an address equal to the encryption key number of the index table. Is read out, and the numerical value read from the index table is subtracted from the content of the address obtained by adding the numerical value indicating the basic unit of the encrypted data to the start address of the decryption conversion table to obtain the decrypted data. Then, the above processing is performed on the entire encrypted data.

According to the third decryption method of the present invention, the contents of the address equal to the encryption key number of the index table are moved backward from the start address of the decryption conversion table by the numerical value indicating the basic unit of the encrypted data. Since the content read from the address of is decrypted data to be decrypted data, it has a decryption conversion table corresponding to all the encryption key numbers that can be determined although it has only one decryption conversion table. It is possible to achieve the security protection equivalent to.

The fourth encryption method of the present invention has one encryption conversion table and one index table for determining a numerical value to be subtracted from the contents read from the encryption conversion table. , The content of the address equal to the randomly determined encryption key number is read, and the value of the basic address of the encrypted data is added to the start address of the encryption conversion table, and the content of the address is read from the index table. The numeric value is subtracted to obtain encrypted data. Then, the above processing is performed over the entire encrypted data, and when the processing is completed, the data is transmitted to the server.

According to the fourth encryption method of the present invention, one encryption conversion table and one index table for determining a numerical value to be subtracted from the contents read from the encryption conversion table are provided, and the index conversion table is provided. The contents of the address in the table that is equal to the randomly determined encryption key number is read out, and the encryption is performed by subtracting from the contents of the address that is the numerical value backward from the start address of the encryption conversion table that displays the basic unit of the encrypted data. Since it is encrypted data, it is possible to realize the same level of security as having an encryption conversion table corresponding to all the encryption key numbers that can be determined, even though it has only one encryption conversion table. it can.

The fourth decoding system of the present invention has one decoding conversion table and one index table for determining the starting point address when referring to the decoding conversion table. Of the address equal to the encryption key number, and the address obtained by adding the numerical value indicating the read content to the start address of the decryption conversion table is used as the starting address of the decryption conversion table, and the decryption conversion table Then, the content of the address obtained by adding a numerical value indicating the content of the basic unit of the encrypted data to the origin address is read out and used as the decrypted data.
Then, this process is performed for the entire encrypted data.

According to the fourth decryption method of the present invention, the contents of the address equal to the encryption key number in the index table are read out, and the read contents are displayed backward from the top address of the decryption conversion table. Is used as the starting address of the decryption conversion table, and the contents of the address after the numerical value indicating the contents of the basic unit of the encrypted data from the starting address of the decryption conversion table are read out to be the decryption data. Therefore, despite having only one decryption conversion table, it is possible to realize security equivalent to having a decryption conversion table corresponding to all the determined encryption key numbers.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of a data processing apparatus to which the encryption system of the present invention is applied, and shows the configuration directly related to the encryption system, taking the form of a client & server system as an example.

In FIG. 1, 1 is a client, and 11
Is a keyboard, 12 is a display device, 13 is input / output (I /
O) control unit, 14 is a central control unit (CPU), and 15 is a random access memory (RAM). On the random access memory, the encrypted data buffer 151 for storing the data to be encrypted, the encryption processing program 152, the encryption conversion table 153 referred to when the encryption processing program encrypts, the encryption Areas of an encrypted data buffer 154 for storing the encrypted data and an encryption key number buffer 155 for storing the encryption key number used at the time of encryption are secured. Reference numeral 2 is a server, 21 is an input / output (I / O) control device, and 22 is a magnetic disk memory, for example. On the magnetic disk memory,
Areas of an encrypted data file 221 for receiving and storing the data encrypted by the client and an encryption key number file 222 for storing the encryption key number used when the client encrypts are secured.

The encrypted data is encrypted by referring to the encryption conversion table, stored in the encrypted data buffer, and stored in the encrypted data buffer when the entire encrypted data has been encrypted. The encryption key number and is sent to the server.

FIG. 2 shows the structure of a data processing apparatus to which the decoding system of the present invention is applied, and shows the structure directly related to the decoding system by taking the form of a client & server system as an example.

In FIG. 2, 1a is a client and 1
1 is a keyboard, 12 is a display device, 13 is input / output (I /
O) controller, 14 is a central controller (CPU), 15a
Is random access memory (RAM). On the random access memory, the decryption data buffer 151a for storing the data to be encrypted, the decryption processing program 156, the decryption conversion table 157 referred to when the decryption processing program decrypts, the encrypted Areas of the encrypted data buffer 154 for storing the data and the encryption key number buffer 155 for storing the encryption key number used at the time of encryption are secured. Reference numeral 2 is a server, 21 is an input / output (I / O) control device, and 22 is a magnetic disk memory, for example. An area of an encrypted data file 221 for receiving and storing data encrypted by the client and an encryption key number file 222 for storing the encryption key number used when the client encrypts the data on the magnetic disk memory. Is secured.

The encrypted data is decrypted by referring to the decryption conversion table, stored in the decrypted data buffer, and when the decryption processing is completed for the entire encrypted data, the contents of the decrypted data buffer are displayed on the display device. Transferred to.

The encryption method or the decryption method applied to the data processing apparatus of FIG. 1 or 2 will be specifically described below. FIG. 3 is a processing procedure of the first encryption method applied to the data processing apparatus of FIG. 1, and FIG. 4 is a diagram for explaining the processing of the first encryption method with specific numerical values. The processing in the first encryption method will be described below with reference to the reference numerals in FIG. 3 and in conjunction with FIG. It is assumed that the encryption / decryption processing is performed for each 1-byte data. C1. When the data to be encrypted is input and the data amount of the data to be encrypted is N bytes, the buffer amount of the encrypted data is determined to be N bytes accordingly. In this case, N =
8 The encrypted data is a kana, alphabet, number, etc., but since the basic unit of the data is 1 byte, all of them are represented by a binary number of 8 bits (1 byte). Therefore, the encrypted data is represented by a number from 0 to 255. Now, it is assumed that the data to be encrypted is 8 bytes and the content is as shown in the "data to be encrypted buffer" in FIG. C2. The encryption key number is determined to be random using a random number table or the like. In this case, since the data to be encrypted is represented by an 8-bit binary number, the encryption key number is also determined from 256 types of 0 to 255. Now, it is assumed that the encryption key number is decided to be 2. C3. The data to be encrypted is represented by 256 kinds of numerical values from 0 to 255, and the encryption key number is 256 from 256 to 0.
Since there are various types, the number of addresses in the encryption conversion table is 256, and the stored contents are determined so that the addresses having different numerical values from 0 to 255 do not overlap. The contents are shown in Figure 4.
As shown in “Encryption conversion table” of.
The same address as the encryption key number in this encryption conversion table is defined as the starting address when referring to the encryption conversion table for encryption. Now the encryption key number is 2
Therefore, the starting address is address 2. C4. An initial value 0 is set to the count value (C) of the counter. C5. Read the Cth byte of the encrypted data buffer. Since C = 0 now, 1 of the 0th byte of the encrypted data buffer is read. C6. From the encryption conversion table, the content of the address obtained by adding 1 read in step C5 to the starting address of the encryption conversion table is read. In this case, since the starting address is 2 and the content of the read data is 1,
The content of address 3 in the encryption conversion table, that is, 3 is read. C7. The content 3 read in step C6 is stored in the C-th byte (currently the 0-th byte) of the encrypted data buffer. C8. The count value is incremented to C = 1. C9. It is determined whether or not the encryption process is completed. In this determination, the current C is 1 and N is 8, so the encryption is not completed. Therefore, the process jumps to step C5.

In step C5, since C = 1 this time, the content 1 is read from the first byte of the encrypted data buffer, and the content of address 3 obtained by adding 1 to the starting address of the encryption conversion table is read in step C6. Is read out and stored in the first byte of the encrypted data buffer in step C7.

If such processing is executed from the 0th byte to the 7th byte of the data buffer to be encrypted, C which has become 8 in step C9 becomes equal to N, so it is judged that the encryption processing has been completed. To be done. C10. The contents of the encrypted data buffer in which the encrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

In FIG. 3, for example, the expression "backward from the starting point by the numerical value of the read data" is used, which means "the address obtained by adding the numerical value of the read data to the starting point address". The word "rearward" is used in the subsequent figures showing the processing procedure, but all have the same meaning.

Although the processing when 2 is determined as the encryption key number has been described above, since the encryption key number is randomly determined, the encryption key number will be used when the encryption processing is performed next. Different values are determined for. If the encryption key number is different, the origin address when referring to the encryption conversion table is naturally different. Therefore, the first encryption method of the present invention is equivalent to having an encryption conversion table corresponding to all the encryption key numbers that can be determined, although it has only one encryption conversion table. Achieves excellent security protection. In other words, even small-scale hardware can achieve the same level of security protection as large-scale hardware,
The cost performance of the encryption method can be improved.

FIG. 5 is a processing procedure of the first decoding method applied to the data processing apparatus of FIG. 2, and FIG. 6 is a diagram for explaining the process of the first decoding method with concrete numerical values. .
Hereinafter, the processing in the first decoding method will be described along with the reference numerals of FIG.

Here, the decoding conversion table of FIG. 6 is shown in FIG.
The content of the encryption conversion table is used as the address of the decryption conversion table, and the address of the encryption conversion table is used as the content of the decryption conversion table. D1. When the encrypted data is input and the data amount of the encrypted data is N bytes, the buffer amount of the decrypted data is determined to be N bytes accordingly. In this case, N = 8. Also, enter the encryption key number. The encryption key number is 2. D2. An initial value 0 is set to the count value (C) of the counter. D3. The content 3 of the 0th byte of the encrypted data buffer is read. D4. An address obtained by adding the content 3 of the read data to the start address of the decoding conversion table, that is, address 3
The content of 3 is read out. D5. The result 1 obtained by subtracting the encryption key number 2 from the content 3 read in step D4 is stored in the 0th byte of the decryption data buffer. D6. The count value of the counter is incremented to C = 1. D7. Since the decoding process has not been completed at this time, the process jumps to step D3.

At D3, the content 3 of the first byte of the encrypted data buffer is read out, and at D4, the content of the address obtained by adding the content read out at D3 to the head of the decryption conversion table, that is, the content of address 3, 3 is read out. Then, 1 which is the result of subtracting 2 of the encryption key number from this is stored in the first byte of the decryption data buffer. The above decryption process is performed for all data in the encrypted data buffer. Then, when it is determined in step D7 that the decoding process is all completed, the process proceeds to step D8. D8. The contents of the decoded data buffer in which the decoded data is stored at all addresses are output and transferred to the display device.

Although the processing when 2 is determined as the encryption key number has been described above, since the encryption key number is determined at random, the next time the decryption processing is performed, the encryption key number is performed. Different values are determined for. If the encryption key number is different, the result of subtracting the content read from the decryption conversion table and the encryption key number is naturally different. In the first decryption method of the present invention, even though it has only one decryption conversion table, it is equivalent to having a decryption conversion table corresponding to all the encryption key numbers that can be determined. Protection can be realized. That is, even small-scale hardware can realize security protection equivalent to that of large-scale hardware, and the cost and performance of the decryption method can be improved.

By the way, comparing the diagram for explaining the encryption process of FIG. 4 with the diagram for explaining the decryption process of FIG. 6, the encrypted data of FIG. 4 and the decryption of FIG. In agreement with the data. Therefore, it can be seen that the processes of FIGS. 4 and 6 are paired processes.

However, FIGS. 4 and 6 only show the encryption process and the decryption process when the encryption key number is determined to be 2, and the encryption process is performed only by the first encryption method. It cannot be said that the data can be restored to the original data by the first decoding method.

FIG. 7 is an example showing that what is encrypted by the first encryption method can be restored by the first decryption method. This is different from the example shown in FIGS. 4 and 6, but due to space limitations, the encrypted data is 2 bits, the number of addresses in the encryption conversion table and the decryption conversion table is 4, and the encryption key number is It is verified that the encrypted data and the decrypted data match for all of (K) 0 to 3.

The encrypted data is shown in the "encrypted data buffer" in FIG. 7, and the encrypted conversion table is shown in the "encrypted conversion table" in FIG. Starting from here, if the same determination as the process of FIG. 4 is made, the encrypted data will be as shown in the “encrypted data buffer” of FIG. Naturally, the encrypted data obtained by the encryption key number is different.

On the other hand, since the decryption conversion table has the contents and addresses of the encryption conversion table exchanged,
It will be the same regardless of the encryption key number. However, when the contents of the decryption conversion table are expressed using the encryption key number K at that time, different expressions correspond to the respective encryption key numbers.

Now, when K = 0, 1 (K + 1) is read from the decryption conversion table with the contents of the 0th byte of the encrypted data buffer. Since the decoded data is obtained by subtracting the value of K from this, the decoded data of the 0th byte becomes 1. 3 is read from the decryption conversion table with the contents of the first byte of the encrypted data buffer.
(K + 3). Since the decoded data is obtained by subtracting the value of K from this, the decoded data of the first byte becomes 3. Similarly, the decrypted data of the second byte and the third byte are 0 and 2.

Next, when K = 1, 2 (K + 1) is read from the decryption conversion table with the contents of the 0th byte of the encrypted data buffer. Since the decoded data is obtained by subtracting the value of K from this, the decoded data of the 0th byte becomes 1. 0 is read from the decryption conversion table with the first byte of the encrypted data buffer
(K + 3). Since the decoded data is obtained by subtracting the value of K from this, the decoded data of the first byte becomes 3. Similarly, the decrypted data of the second byte and the third byte are 0 and 2. That is, it is the same as the decrypted data obtained when K = 0.

When this is performed also when K = 2 and K = 3, it can be seen that the same decoded data as when K = 0 and K = 1 can be obtained. Therefore, in the case of 2-bit data, the process of FIG. 6 can be said to be a reversible process of the process of FIG.

Although the data composed of 2 bits is taken as an example at present, it can be generally proved that the process of FIG. 6 is a reversible process of the process of FIG. The key to this is that the decryption conversion table has the address and contents of the encryption conversion table replaced.

That is, the encryption key number is added to the start address of the encryption conversion table to make the starting address, and the contents of the address obtained by adding the number representing the contents of the encrypted data to the starting address are made the encrypted data. In this case, when decrypting, the decryption conversion table is referred to by using the encrypted data as an address. Since the decryption conversion table is obtained by exchanging the address and the contents of the encryption conversion table, the value stored in the referenced address is the sum of the numerical value of the encrypted data and the origin address. Since the origin address is the encryption key number, if the encryption key number is subtracted from the value read from the referenced address, the result of the subtraction is the encrypted data itself.

The "addition" in the above description means "addition modulo 255". That is, the addition result is 256
When it is above, 256 is 0, 257 is 258 is 2, ...
... is converted like. When the result of subtraction becomes negative, -1 is 255, -2 is 254,-
3 is converted to 253, ...

By the way, in the above, the content of the address obtained by adding the encryption key number to the start address of the encryption conversion table as the starting address and adding the number representing the content of the encrypted data to the starting address is encrypted. As the encrypted data, the numerical value stored in the address obtained by adding the numerical value expressing the encrypted data to the start address of the decryption table is read, and the result obtained by subtracting the encryption key number from the read numerical value is decrypted. Although the encryption and decryption method using data has been described, the present invention is not limited to the above.

That is, the encryption key number is subtracted from the start address of the encryption conversion table to obtain the starting address, and the contents of the address obtained by adding the number representing the contents of the encrypted data to the starting address are the encrypted data. Read the numerical value stored in the address obtained by adding the numerical value expressing the encrypted data to the start address of the decryption table, and add the encryption key number to the read numerical value to obtain the decrypted data. You can also

FIG. 8 is an example (part 2) showing that the data to be encrypted can be restored by the encryption and decryption methods described immediately above. In FIG. 8, the data to be encrypted and the encryption conversion table are the same as in the case of FIG. 7, and the encryption and decryption processes are performed by the method described immediately above.

Starting from this point, if it is obtained in the same manner as in the case of FIG. 7, the encrypted data will be as shown in the "encrypted data buffer" of FIG. 8 corresponding to the encrypted key number. Naturally, the encrypted data obtained by the encryption key number is different.

On the other hand, since the decryption conversion table has the contents and addresses of the encryption conversion table exchanged,
It is the same regardless of the encryption key number, and is also the same in the case of FIG. However, when the contents of the decryption conversion table are expressed using the encryption key number K at that time, different expressions correspond to the respective encryption key numbers.

Now, when K = 0, 1 (1-K) is read from the decryption conversion table with the contents of the 0th byte of the encrypted data buffer. Since the decrypted data is obtained by adding the value of K to this, the decrypted data at the 0th byte becomes 1. 3 is read from the decryption conversion table with the contents of the first byte of the encrypted data buffer.
(3-K). Since the decrypted data is obtained by adding the value of K to this, the decrypted data of the first byte becomes 3. Similarly, the decrypted data of the second byte and the third byte are 0 and 2.

Next, when K = 1, 0 (1-K) is read from the decryption conversion table with the contents of the 0th byte of the encrypted data buffer. Since the decrypted data is obtained by adding the value of K to this, the decrypted data at the 0th byte becomes 1. Only 2 bytes are read from the decryption conversion table with the contents of the first byte of the encrypted data buffer.
(3-K). Since the decrypted data is obtained by adding the value of K to this, the decrypted data of the first byte becomes 3.

Similarly, the decoded data of the second and third bytes are 0 and 2. That is, it is the same as the decrypted data obtained when K = 0. If this is also performed when K = 2 and K = 3, it can be seen that the same decoded data as when K = 0 and K = 1 can be obtained. Therefore,
In the case of 2-bit data, it can be said that it is a reversible process of the encryption and decryption processes described immediately above.

Although the data composed of 2 bits is taken as an example at this point, it can be generally proved that it is a reversible process of the encryption and decryption processes described immediately above. Again, the key is that the decryption conversion table has the address and contents of the encryption conversion table replaced.

That is, the encryption key number is subtracted from the start address of the encryption conversion table to obtain the starting address, and the contents of the address obtained by adding the number representing the contents of the encrypted data to the starting address are the encrypted data. In this case, when decrypting, the decryption conversion table is referred to by using the encrypted data as an address. Since the decryption conversion table is obtained by exchanging the address and the contents of the encryption conversion table, the value stored in the referenced address is the sum of the numerical value of the encrypted data and the origin address. Since the origin address is obtained by changing the sign of the encryption key number, if the encryption key number is added to the value read from the referenced address, the addition result becomes the encrypted data itself.

FIG. 9 is a processing procedure of the second encryption method applied to the data processing apparatus of FIG. 1, and FIG. 10 is a diagram for explaining the process of the second encryption method with specific numerical values. . The processing of the second encryption method of the present invention will be described below with reference to the reference numerals of FIG. 9 and also using FIG. C11. When the data to be encrypted is input and the data amount of the data to be encrypted is N bytes, the buffer amount of the encrypted data is determined to be N bytes accordingly. In this case, N
= 8. C12. The encryption key number is decided to be random using a random number table and time. In this case, it is assumed that the encryption key number is decided to be 2 by chance. C13. An initial value 0 is set to the count value (C) of the counter. C14. Read the Cth byte of the encrypted data buffer. Since C = 0 now, 1 of the 0th byte of the encrypted data buffer is read. C15. The content of the address obtained by adding 1 read in step C14 to the start address of the encryption conversion table is read. In this case, the content 2 of the address 1 of the encryption conversion table is read. C16. The encryption key number 2 is subtracted from the content 2 read in step C15 and the result is stored in the 0th byte of the encrypted data buffer. C8. The count value is incremented to C = 1. C9. It is determined whether or not the encryption process is completed. Since it is not finished at this point, the process jumps to step C14.

At step C14, since C = 1 this time, the content 1 is read from the first byte of the encrypted data buffer, and at step C15, the content 2 of the address 1 obtained by adding 1 to the start address of the encryption conversion table is read.
Is read, and the encryption key number 2 is subtracted from the read content 2 in step C16 and stored in the encrypted data buffer. When the same process is performed for all the encrypted data, the encrypted data shown in the "encrypted data buffer" of FIG. 9 is obtained. C10. The contents of the encrypted data buffer in which the encrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

The second encryption method of the present invention reads the content of the address obtained by adding the content of the encrypted data to the start address of the encryption conversion table, and subtracts the encryption key number from the read content. And make it encrypted data. The encryption key number is randomly determined at each encryption process. Therefore, even if only one encryption conversion table is available, the encryption conversion table corresponding to all the encryption key numbers that can be determined is used. You can achieve the security protection equivalent to having.

FIG. 11 is a processing procedure of the second decoding method applied to the data processing apparatus of FIG. 2, and FIG. 12 is a diagram for explaining the process of the second decoding method with concrete numerical values. . The process of the second decoding method of the present invention will be described below with reference to the reference numerals of FIG. 11 and also using FIG. D9. When the encrypted data is input and the data amount of the encrypted data is N bytes, the buffer amount of the decrypted data is determined to be N bytes accordingly. In this case, N = 8. Also, enter the encryption key number. It is 2 now. D10. The address obtained by adding the encryption key number to the start address of the decryption conversion table is used as the starting point address when referring to the decryption conversion table. In this case, the origin address is 2. D11. An initial value 0 is set to the count value (C) of the counter. D12. Read the C-th byte of the encrypted data buffer. Since C = 0 now, 0 of the 0th byte of the encrypted data buffer is read. D13. The contents of the address obtained by adding 0 read in step D12 to the starting address of the decoding conversion table are read out. In this case, the content 1 of the address 2 in the decoding conversion table is read. D14. The content 1 read in step D13 is stored in the 0th byte of the decoded data buffer. D15. The count value is incremented to C = 1. D16. It is determined whether or not the encryption process is completed. Since it has not ended yet, the process jumps to step D12.

At step D12, since C = 1 this time, the content 0 is read from the first byte of the encrypted data buffer, and at step D13 the content 1 of address 2 obtained by adding 0 to the starting address of the decryption conversion table is read.
Is read and the read content 1 is stored in the decoded data buffer in step D15. When the same process is performed on all the encrypted data, the decrypted data shown in the "decrypted data buffer" of FIG. 11 is obtained. D17. The contents of the decoded data buffer in which the decoded data is written in all the addresses are output and transferred to the display device.

According to the second decryption method of the present invention, the content of the address obtained by adding the content of the encrypted data to the starting address of the decryption conversion table is read, and the read content is used as the decrypted data. The origin address is determined by adding the encryption key number to the start address of the encryption conversion table, and the encryption key number is randomly determined at each encryption process, so only one decryption conversion table is available. Even if there is no encryption key number, it is possible to realize security equivalent to having a decryption conversion table corresponding to all the encryption key numbers that can be determined.

By the way, comparing the diagram for explaining the encryption process of FIG. 10 with the diagram for explaining the decryption process of FIG. 12, the encrypted data of FIG. 10 and the decryption data of FIG. In agreement with the data. Therefore, when the encryption key number is 2, it can be seen that the processes of FIGS. 10 and 12 are a pair of processes.

That is, since the address of the encryption conversion table is designated by the data to be encrypted, the address of the encryption conversion table is equal to the data to be encrypted. This is stored in the decoding conversion table. By the way, the encrypted data is obtained by subtracting the encryption key number from the content stored in the encryption conversion table, that is, the content stored in the encryption conversion table has the encryption key number added to the encrypted data. It is the sum. This is an address in the decoding conversion table. Therefore, the address to be selected when referring to the decryption conversion table must be the address obtained by adding the encryption key number to the encrypted data. Therefore, using the address obtained by adding the encryption key number to the start address of the decryption conversion table as the starting address,
By referring to the address obtained by adding the numerical value expressing the encrypted data to the starting point address, the address is the address obtained by adding the encryption key number to the encrypted data.
Therefore, referring to this address, the stored numerical value is the encrypted data itself.

In the above, in the encryption conversion table,
The decryption conversion table is obtained by reading the numerical value stored in the address obtained by adding the number representing the data to be encrypted to the head address, and subtracting the encryption key number from the read numerical value to obtain the encrypted data. The address obtained by adding the encryption key number to the start address of the address is used as a starting point address when referring to the decryption conversion table, and an address obtained by adding a numerical value expressing encrypted data to the starting point address in the decryption conversion table Although the encryption and the decryption method using the numerical value stored in the above as the decrypted data have been described, the present invention is not limited to the above.

That is, in the encryption conversion table, the numerical value stored in the address obtained by adding the number expressing the data to be encrypted to the head address is read, and the encryption key number is added to the read numerical value. The numeric value is the encrypted data, the address obtained by subtracting the encryption key number from the start address of the decryption conversion table is the starting point address when referring to the decryption conversion table, and the starting point address of the decryption conversion table is The same operation can be performed by the encryption and the decryption method in which the numerical value stored in the address to which the numerical value expressing the encrypted data is added is the decrypted data. Since the combination of the first encryption method and the first decryption method has already been described in detail, only the conclusion will be described as follows.

That is, since the address of the encryption conversion table is designated by the data to be encrypted, the address of the encryption conversion table is equal to the data to be encrypted. This is stored in the decoding conversion table. By the way, the encrypted data is obtained by adding the encryption key number to the content stored in the encryption conversion table, that is, the content stored in the encryption conversion table is the encryption key number from the encrypted data. It has been subtracted. This is an address in the decoding conversion table. Therefore, the address to be selected when referring to the decryption conversion table must be the address obtained by subtracting the encryption key number from the encrypted data. Therefore, if the address obtained by adding the encryption key number to the start address of the decryption conversion table is used as the starting address and the address obtained by adding the numerical value expressing the encrypted data from the starting address is referred to, the address is The address is the address obtained by subtracting the encryption key number. Therefore, referring to this address, the stored numerical value is the encrypted data itself.

FIG. 13 shows the configuration of the second data processing apparatus to which the encryption system of the present invention is applied, and shows the configuration directly related to the encryption system by taking the form of the client & server system as an example.

In FIG. 13, 1b is a client,
11 is a keyboard, 12 is a display device, and 13 is input / output (I
/ O) controller, 14 is a central controller (CPU), 15
b is a random access memory (RAM). On the random access memory, the encrypted data buffer 151 for storing the data to be encrypted, the encryption processing program 152, the encryption conversion table 153 referred to when the encryption processing program encrypts, the encryption An encrypted data buffer 154 for storing the encrypted data, an encryption key number buffer 155 for storing the encryption key number used for encryption, and an index table 158 for determining the starting point for referring to the encryption conversion table. The area is reserved. 2 is a server, 21 is input / output (I
/ O) controller, 22 is, for example, a magnetic disk memory. An area of an encrypted data file 221 for receiving and storing data encrypted by the client and an encryption key number file 222 for storing the encryption key number used when the client encrypts the data on the magnetic disk memory. Is secured.

The encrypted data is encrypted by referring to the encryption conversion table, stored in the encrypted data buffer, and stored in the encrypted data buffer when the entire encrypted data is encrypted. The encryption key number and is sent to the server.

FIG. 14 shows the configuration of the second data processing device to which the decryption system of the present invention is applied, and shows the configuration directly related to the decryption system by taking the form of the client & server system as an example.

In FIG. 14, 1c is a client,
11 is a keyboard, 12 is a display device, and 13 is input / output (I
/ O) controller, 14 is a central controller (CPU), 15
c is a random access memory (RAM). On the random access memory, the decryption data buffer 151a for storing the data to be encrypted, the decryption processing program 156, the decryption conversion table 157 referred to when the decryption processing program decrypts, the encrypted Data buffer 154 for storing stored data, encryption key number buffer 155 for storing the encryption key number used for encryption, index table for determining the starting address when referring to the decryption conversion table The area of 158 is secured. 2 is a server, 21
Is an input / output (I / O) control device, and 22 is a magnetic disk memory, for example. An area of an encrypted data file 221 for receiving and storing data encrypted by the client and an encryption key number file 222 for storing the encryption key number used when the client encrypts the data on the magnetic disk memory. Is secured.

The encrypted data is decrypted by referring to the decryption conversion table, stored in the decrypted data buffer, and the content of the decrypted data buffer is displayed on the display device when the decryption process is completed for the entire encrypted data. Transferred to.

Embodiments of the encryption system and the decryption system in the second data processing device shown in FIGS. 13 and 14 will be described below. FIG. 15 is a processing procedure of the third encryption method of the present invention applied to the data processing apparatus of FIG.
FIG. 10 is a diagram for explaining the encryption process with specific numerical values for the third encryption method. Hereinafter, the processing of the third encryption method will be described along with the reference numerals of FIG. 15 and also using FIG. C20. When the data to be encrypted is input and the data amount of the data to be encrypted is N bytes, the buffer amount of the encrypted data is determined to be N bytes accordingly. In this case, N
= 8. C21. The encryption key number is decided to be random using a random number table and time. In this case, it is assumed that the encryption key number is decided to be 253. C22. The same address as the encryption key number in the index table is defined as the starting point address that serves as a reference when referring to the encryption conversion table for encryption. Since the encryption key number is 253 at this time, it is index 2. C23. The address obtained by adding the index 2 to the leading address of the encryption conversion table is determined as the starting address of the encryption conversion table. C24. An initial value 0 is set to the count value (C) of the counter. C25. Read the Cth byte of the encrypted data buffer. Since C = 0 now, 1 of the 0th byte of the encrypted data buffer is read. C26. From the encryption conversion table, the content of the address obtained by adding 1 read in step C25 to the starting point address of the encryption conversion table is read. In this case, since the starting address is 2 and the content of the read data is 1, the content 3 of the address 3 in the encryption conversion table is read. C27. The content 3 read in step C26 is stored in the C-th byte (currently the 0-th byte) of the encrypted data buffer. C28. The count value is incremented to C = 1. C29. It is determined whether or not the encryption process is completed. In this determination, the current C is 1 and N is 8, so the encryption is not completed. Therefore, the process jumps to step C25.

Since C = 1 this time in step C25, the content 1 is read from the first byte of the data buffer to be encrypted, and the content of address 3 obtained by adding 1 to the starting address of the encryption conversion table is read in step C26. 3 is read out and stored in the first byte of the encrypted data buffer in step C27.

If such processing is executed from the 0th byte to the 7th byte of the data buffer to be encrypted, C which has become 8 in step C9 becomes equal to N, so it is judged that the encryption processing has been completed. To be done. C30. The contents of the encrypted data buffer in which the encrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

The third encryption method of the present invention has one encryption conversion table and one index table,
The encryption key number determines the index, and the index determines the starting address of the encryption conversion table. Since the encryption key number is randomly determined, the third encryption method of the present invention can realize security equivalent to having an encryption conversion table corresponding to all the encryption key numbers that can be determined. .

Further, the third encryption method of the present invention is characterized in that, in order to determine the starting address of the encryption conversion table, the index is determined by the encryption key number and the starting point of the encryption conversion table is determined by the index. It is a two-step decision process of deciding an address.
By doing so, even if the encryption key number is known, it is less likely that even the reference location of the encryption conversion table will be known, and the confidentiality of the first and second encryptions of the present invention is improved. It will be higher than the method.

FIG. 17 describes the processing procedure of the third decoding method of the present invention applied to the data processing apparatus of FIG. 14, and FIG. 18 describes the decoding process with specific numerical values for the third decoding method. FIG. Hereinafter, along the reference numerals of FIG.
Processing of the third encryption method will be described with reference to FIG. D18. When the encrypted data is input and the data amount of the encrypted data is N bytes, the buffer amount of the decrypted data is determined to be N bytes accordingly. In this case, N = 8
It is. Also, enter the encryption key number. The encryption key number is 253 in this case. D19. The content of the address obtained by adding the encryption key number to the head of the index table is determined as the index.
In this case, 2 of the contents of the address 253 becomes the index. D20. An initial value 0 is set to the count value (C) of the counter. D21. Read the C-th byte of the encrypted data buffer. Since C = 0 now, the 0th byte 3 of the encrypted data buffer is read. D22: Content 3 read in step D21 from the decoding conversion table to the start address of the decoding conversion table
Read the contents of the address to which is added. In this case, the content 3 of the address 3 in the decoding conversion table is read. D23. The index 2 is subtracted from the content 3 read in step D22, and the result 1 is stored in the C-th byte (currently the 0-th byte) of the decoded data buffer. D24. The count value is incremented to C = 1. D25. It is determined whether or not the encryption process is completed. In this determination, the current C is 1 and N is 8, so the encryption is not completed. Therefore, the process jumps to step D21.

Since C = 1 this time in step D21, the content 3 is read from the first byte of the encrypted data buffer, and the content 3 of address 3 obtained by adding 3 to the head address of the decryption conversion table is read in step D22.
Is read and the index 2 is subtracted from the read content 3 in step D23, and the result 1 is stored in the first byte of the decoded data buffer.

If such processing is executed from the 0th byte to the 7th byte of the data buffer to be encrypted, C which has become 8 in step D24 becomes equal to N, so it is judged that the encryption processing has been completed. To be done. D26. The contents of the decrypted data buffer in which the decrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

The third decoding method of the present invention has one decoding conversion table and one index table,
The index is determined by the encryption key number, and the index is subtracted from the contents read from the decryption conversion table to determine the decrypted data. Since the encryption key number is randomly determined, the third decryption method of the present invention can realize security equivalent to having a decryption conversion table corresponding to all the encryption key numbers that can be determined. .

Further, the third decoding system of the present invention is characterized in that when determining the number to be subtracted from the contents read from the decoding conversion table, the index is determined by the encryption key number, and the index is determined. It is a two-step decision process of setting the number to be subtracted. By doing this, even if the encryption key number is known, the possibility that the number subtracted from the data read from the decryption conversion table will be known becomes low,
The security is higher than that of the first and second decoding methods of the present invention.

The fact that the process of the third encryption system and the process of the third decryption system are reversible processes means that the process of the third encryption system shown in FIG. 16 and the process of the third encryption system shown in FIG. In the process of the third decryption method, the starting point address at the time of encryption is determined via the index table, and the number to be subtracted at the time of decryption is determined. This can be easily understood by considering that the essential processes of encryption and decryption are the same as those of the first encryption system and the first decryption system, only different from the system.

The action of the index in the processing of the third encryption method and the processing of the third decryption method is the encryption key number in the processing of the first encryption method and the processing of the first decryption method. The same modification as the modification regarding the encryption key number in the processing of the first encryption method and the processing of the first decryption method is the same as the operation of the third encryption method and the third decryption. It is also possible for the index in the processing of the coding method.

FIG. 19 illustrates the processing procedure of the fourth encryption method of the present invention applied to the data processing apparatus of FIG. 13, and FIG. 20 illustrates the encryption process with specific numerical values for the fourth encryption method. FIG. Hereinafter, along the reference numerals of FIG.
Processing of the fourth encryption method will be described with reference to FIG. C31. When the data to be encrypted is input and the data amount of the data to be encrypted is N bytes, the buffer amount of the encrypted data is determined to be N bytes accordingly. In this case, N
= 8. C32. The encryption key number is decided to be random using a random number table and time. In this case, it is assumed that the encryption key number is decided to be 253. C33. The content of the same address as the encryption key number in the index table is determined as the index. Now, since the encryption key number is 253, the index is 2. C34. An initial value 0 is set to the count value (C) of the counter. C35. The contents of the C byte of the encrypted data buffer are read. Now, 1 of the 0th byte is read. C36. The content of the address obtained by adding 1 read in step C36 to the start address of the encryption conversion table is read. In this case, the content 2 of the address 1 in the encryption conversion table is read. C37. The index 2 is subtracted from the content 2 read in step C36, and the resulting 0 is stored in the Cth byte (currently the 0th byte) of the encrypted data buffer. C38. The count value is incremented to C = 1. C39. It is determined whether or not the encryption process is completed. In this determination, the current C is 1 and N is 8, so the encryption is not completed. Therefore, the process jumps to step C35.

Since C = 1 this time in step C35, the content 1 is read from the first byte of the encrypted data buffer, and the content of address 1 obtained by adding 1 to the start address of the encryption conversion table is read in step C36. 2, the index 2 is subtracted from the read content 2 in step C37, and the result is stored in the first byte of the encrypted data buffer.

If such a process is executed from the 0th byte to the 7th byte of the data buffer to be encrypted, C which has become 8 in step C9 becomes equal to N, so it is judged that the encryption process is completed. To be done. C40. The contents of the encrypted data buffer in which the encrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

Also in the fourth encryption system of the present invention, one encryption conversion table and one index table are provided,
Determine the encrypted data. Therefore, similar to the first and second encryption methods of the present invention, it is possible to realize security protection equivalent to having an encryption conversion table corresponding to all the determined encryption key numbers.

Further, the feature of the fourth encryption method of the present invention is that the index is once determined by using the encryption key number in order to determine the number to be subtracted from the contents read from the encryption conversion table. , A two-step process of determining the index to be subtracted. By doing so, even if the encryption key number is known, it is less likely that the number subtracted from the contents of the encryption conversion table will be known, and the confidentiality can be protected by the first and second aspects of the present invention. It is higher than the encryption method of.

FIG. 21 shows the processing procedure of the fourth decoding method of the present invention applied to the data processing apparatus of FIG. 14, and FIG. 22 shows the decoding process of the fourth decoding method with concrete numerical values. FIG. Hereinafter, along the reference numerals of FIG.
Processing of the fourth decoding method will be described with reference to FIG. D27. When the encrypted data is input and the data amount of the encrypted data is N bytes, the buffer amount of the decrypted data is determined to be N bytes accordingly. In this case, N = 8
It is. Also, enter the encryption key number. The encryption key number is 253 in this case. D28. The content of the address after the encryption key number from the beginning of the index table is determined as the index. In this case, 2 of the contents of the address 253 becomes the index. D29. An address obtained by adding the index 2 to the head address of the decoding conversion table is determined as the starting address of the decoding conversion table. In this case, since the index is 2, the address 2 in the decoding conversion table is the starting point address. D30. An initial value 0 is set to the count value (C) of the counter. D31. Read the C-th byte of the encrypted data buffer. Since C = 0 now, 0 of the 0th byte of the encrypted data buffer is read. D32. From the decryption conversion table, the content 0 read in step D31 to the starting address of the decryption conversion table
Read the contents of the address to which is added. In this case, the content 4 of the address 0 in the decoding conversion table is read. D33. The content 3 read out in step D32 is stored in the C-th byte (currently the 0-th byte) of the decoded data buffer. D34. The count value is incremented to C = 1. D35. It is determined whether or not the encryption process is completed. In this determination, the current C is 1 and N is 8, so the encryption is not completed. Therefore, the process jumps to step D31.

Since C = 1 this time in step D31, the content 0 is read from the first byte of the encrypted data buffer, and the content 1 of address 2 obtained by adding 0 to the starting address of the decryption conversion table is read in step D32.
Is read and stored in the first byte of the decoded data buffer in step D33.

If such a process is executed from the 0th byte to the 7th byte of the data buffer to be encrypted, C which becomes 8 in step D24 becomes equal to N, so it is judged that the encryption process is completed. To be done. D36. The contents of the decrypted data buffer in which the decrypted data is written in all the addresses and the contents of the encryption key number buffer are transmitted to the server.

Also in the fourth decoding system of the present invention, the decoded data is determined by having one decoding conversion table and one index table. Since the encryption key number is randomly determined, the fourth decryption method of the present invention can realize security equivalent to having a decryption conversion table corresponding to all the encryption key numbers that can be determined. .

Further, the fourth decoding system of the present invention is characterized in that when determining an address for referring to the decryption conversion table, an index is determined by an encryption key number and the index is used as the starting point of the decryption conversion table. It is a two-step decision process of deciding on an address. By doing so, even if the encryption key number is known, it is less likely that the origin address of the decryption conversion table will be known, and the confidentiality can be protected by the first and second decryption methods of the present invention. It will be higher than the method.

The fact that the process of the fourth encryption system and the process of the fourth decryption system are reversible processes means that the process of the fourth encryption system and the process of the fourth decryption system are indexes. Only the difference between the first encryption method and the first decryption method is that the number to be subtracted at the time of encryption is determined via the table and the index at the time of decryption is determined. This can be easily understood by considering that the essential processing of is the same as the second encryption method and the second decryption method.

The function of the index in the processing of the fourth encryption method and the processing of the fourth decryption method is the encryption key number in the processing of the second encryption method and the processing of the second decryption method. The same modification as the modification relating to the encryption key number in the processing of the second encryption method and the processing of the second decryption method is the same as that of the fourth encryption method and the fourth decryption. It is also possible for the index in the processing of the coding method.

By the way, in the above, the client & server described consistently in FIG. 1 or FIG. 2 or FIG. 13 or FIG.
The encryption method and the decryption method of the present invention have been described with an application to a system-type data processing device and one-way communication such as data transmission in mind. In such a case, when viewed at a certain moment, the specific client is configured to execute one of the encryption method and the decryption method.

However, the function of the client & server system is not limited to one-way communication. or,
Communication with high confidentiality is not limited to the client & server system, and communication may be carried out with confidentiality even in a normal communication system. Moreover, in a normal communication system, the weight of bidirectional communication is high.

Therefore, it is also required for the data processing device that performs bidirectional communication to be able to perform encryption and decryption at the same time. In order to realize this, the bidirectional data processing device is independently equipped with a configuration for performing encryption and a configuration for performing decryption, and the bidirectional data processing device is originally equipped with an encryption unit for encryption. The output of the receiving unit originally provided in the bidirectional data processing device may be supplied to the decoding unit. Therefore, specific hardware is required or connection is required according to a reference interface, but since these technologies have already been put into practical use, description thereof will be omitted here.

[0107]

As described above in detail, according to the first and second encryption methods or the decryption methods of the present invention, all the determinations can be made by only having one encryption conversion table or decryption conversion table. It is possible to realize security equivalent to having an encryption conversion table or a decryption conversion table corresponding to the encryption key number.

Further, the third and fourth encryption systems or decryption systems of the present invention can further enhance the security protection. Furthermore, if the encryption method and the decryption method of the present invention are applied, the capacity of the encryption conversion table and the decryption conversion table can be small, so that the scale of the data processing apparatus can be reduced, and the data processing apparatus can be reduced. Can be for one-way communication or for two-way communication.

[Brief description of the drawings]

FIG. 1 is a configuration of a data processing device to which an encryption method of the present invention is applied.

FIG. 2 is a configuration of a data processing device to which the decoding system of the present invention is applied.

FIG. 3 is a processing procedure of a first encryption method.

FIG. 4 is a diagram for explaining the processing of the first encryption method with specific numerical values.

FIG. 5 is a processing procedure of the first decoding method.

FIG. 6 is a diagram for explaining the processing of the first decoding method with specific numerical values.

FIG. 7 is an example (1) showing that restoration is possible.

FIG. 8 is an example (part 2) showing that restoration is possible.

FIG. 9 is a processing procedure of the second encryption method.

FIG. 10 is a diagram for explaining the processing of the second encryption method with specific numerical values.

FIG. 11 is a processing procedure of the second decoding method.

FIG. 12 is a diagram for explaining the process of the second decoding method with specific numerical values.

FIG. 13 is a configuration of a second data processing device to which the encryption system of the present invention is applied.

FIG. 14 is a configuration of a second data processing device to which the decoding system of the present invention is applied.

FIG. 15 shows a processing procedure of a third encryption method.

FIG. 16 is a diagram for explaining the processing of the third encryption method with specific numerical values.

FIG. 17 is a processing procedure of the third decoding method.

FIG. 18 is a diagram for explaining the processing of the third decoding method with specific numerical values.

FIG. 19 is a processing procedure of a fourth encryption method.

FIG. 20 is a diagram for explaining the process of the fourth encryption method with specific numerical values.

FIG. 21 is a processing procedure of the fourth decoding method.

FIG. 22 is a diagram for explaining the process of the fourth decoding method with specific numerical values.

FIG. 23 is a configuration of a data processing device to which a conventional encryption method is applied.

[Explanation of symbols]

 1 Client 2 Server 11 Keyboard 12 Display Device 13 Input / Output (I / O) Control Device 14 Central Control Unit (CPU) 15 Random Access Memory (RAM) 21 Input / Output (I / O) Control Device 22 Magnetic Disk Memory 151 Encrypted data buffer 152 Encryption processing program 153 Encryption conversion table 154 Encrypted data buffer 155 Encrypted key number buffer 221 Encrypted data file 222 Encrypted key number file

Claims (11)

[Claims] 1. An encryption conversion table in which a number that can be represented by the number of bits of encrypted data is used as an address and the number that can be represented by the number of bits of encrypted data is stored in each address without duplication. And an address obtained by adding an encryption key number randomly determined from a number that can be represented by the number of bits of data to be encrypted to the start address of the encryption conversion table, or the encryption from the start address. An address obtained by subtracting the key number is used as a starting point address when referring to the encryption conversion table, and the starting point address of the encryption conversion table is stored in an address obtained by adding a numerical value expressing the data to be encrypted. An encryption method that uses numerical values as encrypted data. 2. The encryption conversion table according to claim 1, comprising one decryption conversion table in which an address and a stored numerical value are exchanged, and the encryption method according to claim 1, When the address obtained by adding the encryption key number to the start address is used as the starting point address, the value stored in the address obtained by adding the value representing the encrypted data to the start address of the decryption conversion table The decryption data is the result of reading and subtracting the encryption key number from the read numerical value, and in the encryption method according to claim 1, the encryption key number is assigned from the top address of the encryption conversion table. When the subtracted address is used as the starting address, an address obtained by adding a numerical value expressing encrypted data to the head address of the decryption conversion table is added. It reads the value stored in the scan, the decoding scheme, characterized in that the decoded data the result of adding this encryption key ID to the read value. 3. An encryption conversion table in which the number that can be represented by the number of bits of encrypted data is used as an address and the number that can be represented by the number of bits of encrypted data is stored in each address without duplication. Read the numerical value stored in the address obtained by adding the numerical value expressing the encrypted data to the start address from the encryption conversion table, and the number of bits of the encrypted data from the read numerical value. It is characterized in that a numerical value obtained by subtracting an encryption key number randomly determined from the number that can be expressed by or a numerical value obtained by adding the encryption key number to the read numerical value is used as encrypted data. Encryption method. 4. An encryption conversion table according to claim 3, comprising one decryption conversion table in which an address of the encryption conversion table according to claim 3 is exchanged with a stored numerical value. When the value obtained by subtracting the encryption key number from the read value is the encrypted data, the address obtained by adding the encryption key number to the start address of the decryption conversion table is referred to the decryption conversion table. A numerical value stored in an address obtained by adding a numerical value expressing the encrypted data to the starting address of the decryption conversion table is used as a starting address when performing reading, and the read numerical value is used as decrypted data. In the encryption method according to Item 3, a value obtained by adding the encryption key number to a value read from the encryption conversion table is used as encrypted data. In this case, the address obtained by subtracting the encryption key number from the start address of the decryption conversion table is used as the starting point address when referring to the decryption conversion table, and the encrypted data is added to the starting point address of the decryption conversion table. A decoding method characterized in that a numerical value stored at an address to which a numerical value expressing is expressed is read and the read numerical value is decoded data. 5. An index table in which a number that can be expressed by the number of bits of encrypted data is used as an address, and the number that can be expressed by the number of bits of encrypted data is stored in each address without duplication. The number of bits that can be represented by the number of bits of encrypted data is used as an address, and each address is provided with one encryption conversion table that stores the number that can be represented by the number of bits of encrypted data without duplication. The number stored in the address equal to the encryption key number randomly determined from the number that can be represented by the number of bits of the encrypted data in the table is used as the index, and the index conversion is performed at the beginning address of the encryption conversion table. The address obtained by adding the index or the address obtained by subtracting the index from the start address is used as the starting address, An encryption method, wherein a numerical value stored in an address obtained by adding a numerical value expressing data to be encrypted to the origin address is read as encrypted data. 6. An index table according to claim 5, and a decryption conversion table in which an address of the encryption conversion table according to claim is exchanged with a stored numerical value, A number stored in an address equal to the encryption key number is used as an index, and an address obtained by adding the index to the start address of the encryption conversion table is used as an origin address in the encryption method according to claim 5. Read the numerical value stored at the address obtained by adding the numerical value expressing the encrypted data to the start address of the decryption conversion table, and subtracting the index from the read numerical value as the decrypted data. The encryption method according to claim 5, wherein the index is read from the start address of the encryption conversion table. When the address obtained by subtracting the index is used as the starting point address, the numerical value stored in the address obtained by adding the numerical value expressing the encrypted data to the start address of the decryption conversion table is read, and the read numerical value is set to the read numerical value. A decoding method, wherein the result of adding the indexes is used as decoded data. 7. An index table in which a number that can be represented by the number of bits of encrypted data is used as an address, and the number that can be represented by the number of bits of encrypted data is stored in each address without duplication. The number of bits that can be represented by the number of bits of encrypted data is used as an address, and each address is provided with one encryption conversion table that stores the number that can be represented by the number of bits of encrypted data without duplication. From the number that can be represented by the number of bits of the data to be encrypted in the table, the numerical value stored at the address equal to the encryption key number randomly determined is used as the index, and the start address of the encryption conversion table The numerical value stored in the address to which the numerical value expressing the data to be encrypted is added is read, and the read numerical value Index subtraction result, or of the encryption conversion table,
An encryption characterized in that the numerical value stored in the address obtained by adding the numerical value expressing the data to be encrypted to the head address is read, and the result obtained by adding the index to the read numerical value is the encrypted data. method. 8. An index table according to claim 7, and a decryption conversion table in which the address and the stored numerical value of the encryption conversion table according to claim 7 are exchanged. The numerical value stored in the address equal to the encryption key number is used as an index, and in the encryption method according to claim 7, the result obtained by subtracting the index from the numerical value read from the encryption conversion table is the encrypted data. In this case, the address obtained by adding the index to the start address of the decryption conversion table is set as the starting point address, and the starting address of the decryption conversion table is stored at the address obtained by adding the numerical value expressing the encrypted data. 8. The encryption method according to claim 7, wherein the read numerical value is used as decrypted data. When the result obtained by adding the index to the numerical value read from the conversion table is the encrypted data, the address obtained by subtracting the index from the head address of the decryption conversion table is used as the starting point address, and the decryption conversion table A decryption method, wherein a numeric value stored in an address obtained by adding a numeric value expressing encrypted data to the origin address is read as decrypted data. 9. A data processing device comprising the configuration of the encryption system according to claim 1, claim 3, claim 5, or claim 7. 10. A data processing apparatus comprising the configuration of the decoding system according to claim 2, claim 4, claim 6, or claim 8. 11. The decryption method according to claim 2, claim 4, claim 6, or claim 8 with the configuration of the encryption method according to claim 1, claim 3, claim 5, or claim 7. A data processing device having a system configuration.