JP2927079B2 - Data encryption method and data encryption device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data encryption method used for encrypting data, and a data encryption apparatus for realizing the data encryption method.

[0002]

2. Description of the Related Art A conventional data encryption apparatus is disclosed in, for example, Japanese Patent Publication No. 59-36463.

FIG. 5 shows a block diagram of this conventional data encryption device, wherein 501 is a substitution device for processing 64-bit input data, and 502 is a first storage device for storing the right 32 bits of the processed data. The storage device 503 is a second storage device 504 for storing the left 32 bits of the processing data.
Is a function device that inputs 32-bit data and key data, converts the data into random numbers, and outputs randomized 32-bit data, and 505 inputs two 32-bit data and outputs exclusive OR of each bit. An exclusive-OR device for outputting 32-bit data as a result of the operation,
Substitution device for processing output data of bit data, 507
Is a one-stage agitation processing device including a first storage device 502, a second storage device 503, a function device 504, and an exclusive OR device 505, and the agitation processing device is connected to a plurality of stages.

In the conventional encryption device configured as described above, when a 64-bit plaintext is input, the data is exchanged by the substitution device 501 and then divided into 32 bits each. 32 bits first
In the storage device 502, the left 32 bits are stored in the second storage device 50.
3 respectively. Then, the following processing is performed for 1
A plurality of stages of processing are performed as stages. The i-th
The processing of the stage is shown.

The right 32-bit data stored in the first storage device 502 at the preceding stage is stored as it is in the second storage device 503 at the next stage, and the function device 504 is stored in the second storage device 503 at the next stage.
And a function operation is performed by the intermediate key Ki that is input at the same time. As a result, the 32-bit data output from the function device 504 and the left 32-bit data stored in the second storage device 503 are combined with the exclusive OR device 50.
5, an exclusive OR operation is performed for each bit, and the result is stored in the first storage device 502 at the next stage.

After repeating the above processing 16 times, 64-bit data obtained by combining 32-bit data stored in the first storage device 502 and the second storage device 503 is input to the substitution device 506. Subsequently, 64-bit data resulting from the data exchange performed by the character substitution device 506 is output as final encrypted output data.

[0007]

However, in the above-described configuration, only the function device 504 performs the stirring process in the stirring device 507, and the repetition processing of 16 stages is performed by using the same function device using one function device. The stirring process according to the procedure is merely repeated 16 steps. Therefore, 1
There is a problem that there is a possibility that the entire encryption device can be decrypted only by analyzing the processing of the stage.

In view of the above, the present invention provides a structure in which a plurality of function devices for performing stirring are prepared and the function device to be used for the stirring process is determined based on an input value.
It is an object of the present invention to provide an encryption device in which the stirring process at each stage is not fixed and makes decryption difficult.

[0009]

Means for Solving the Problems The present invention, and an even number of storage devices for holding a plurality of block data each, odd
The block data and the block key data held in the (even) th storage device are input, and the block data
Agitating process which is determined by the value of the data, the data randomizing unit for outputting <br/> block data of the result, even (odd)
Block data held in the storage device of the number
When the front SL performs exclusive OR operation on the output of the data stirrer, arithmetic unit and, odd (even) number-th said storage block data held in said arithmetic unit from the output for outputting the block data And a data exchange device for exchanging the block data to be performed in units of blocks, and a configuration in which the processing by the encryption processing device is repeated a predetermined number of times.

[0010]

According to the present invention, a control signal is generated by the control device based on the result of comparing the block data held in the odd-numbered storage device, and the selection switch is switched by the control of the control signal to stir. Since the agitation function device to be used is determined, it is possible to produce an effect as if a different agitation method is employed at each repetition stage of the repetition processing. Further, it is possible to configure a data encryption device in which the stirring method is changed depending on the value of the input data.

[0011]

FIG. 1 shows a block diagram of a one-stage encryption processing device of a data encryption device according to a first embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a first storage device that holds the leftmost 16-bit block data, and reference numeral 12 denotes a second storage device that holds the second 16-bit block data from the left.
The storage device, 13 is a third storage device for holding the third 16-bit block data from the left, and 14 is the fourth 1-bit data from the left.
A fourth storage device for holding 6-bit block data, 20
Is a control device for comparing the 16-bit block data held in the first storage device 11 with the 16-bit block data held in the third storage device 13 to generate two control signals, and 31 is a 16-bit block key A first data agitation device that inputs data and 16-bit block data held in the first storage device 11 and performs agitation under control of a control signal.
This is a second data agitation device that inputs 16-bit block data held in the storage device 13 and performs agitation under control of a control signal.

Reference numeral 41 denotes 16-bit block data held in the second storage device 12 and the first data agitating device 31
The first arithmetic unit 42 that performs an exclusive OR operation for each bit of the 16-bit block data output from the unit and outputs the resulting 16-bit block data
The exclusive OR operation is performed for each bit of the 16-bit block data stored in the second data agitator 32 and the 16-bit block data output from the second data agitating device 32.
The second arithmetic unit 50 that outputs the bit block data converts the 16-bit block data stored in the first storage device 41 to the second 16-bit block data from the left, and stores the 16-bit block data stored in the third storage device 13. The bit block data is the fourth 16-bit block data from the left, the 16-bit block data output from the first arithmetic unit 31 is the third 16-bit block data from the left,
This is a data exchange device that uses the 16-bit block data output from the second arithmetic unit 42 as the leftmost 16-bit block data.

FIG. 2 is a block diagram of a data encryption device according to this embodiment. In FIG. 2, reference numeral 110 denotes an input data processing device that divides input 64-bit data into four 16-bit block data, and 120 denotes a first storage device 11 and a second storage device 1 illustrated in FIG. 1.
2, third storage device 13, fourth storage device 14, control device 2
0, first data stirrer 31, second data stirrer 3
2, a first-stage encryption device 41, which is composed of a first arithmetic device 41, a second arithmetic device 42, and a data exchange device 50, which receives four 16-bit block data and outputs four 16-bit block data; An iterative device that is composed of eight stages of encryption processing devices 120 and that inputs four 16-bit block data and outputs four 16-bit block data. A 140 combines four 16-bit block data output from the repetition device 130. This is an output data processing device that converts the data into 64-bit data.

FIG. 3 is a view showing the embodiment (FIG. 1).
FIG. 3 is a configuration diagram of a first data stirring device 31 and a second data stirring device 32 shown in FIG. In FIG. 3, reference numeral 211 denotes a first agitation function device that inputs 16-bit block data and 16-bit block key data and outputs 16-bit block data as a result of agitation, and 212 denotes a 16-bit block data and a 16-bit block key. A second agitation function device for inputting data and outputting 16-bit block data as a result of agitation, and 220 for converting the input 16-bit block data and 16-bit block key data into the first agitation function device 211 or the second agitation function device 212 to the stirring function device selected by the control signal,
A selection switch for outputting 16-bit block data as a result of stirring.

The operation of the data encryption apparatus according to this embodiment configured as described above will be described below.

First, the input 64-bit data is divided into four 16-bit block data by the input data processing device 110 and input to the repetition device 130. The data input to the repetition device 130 is input to the output data processing device 140 as four encrypted 16-bit block data after eight stages of processing by the encryption processing device 120 are repeated. Output data processing device 140
Then, four 16-bit block data are combined and output as encrypted 64-bit data.

The processing in the one-stage encryption processing unit 120 shown in FIG. 1 will be described below. First, the encryption processing device 12
The four 16-bit block data input to the first storage device 11, the second storage device 12, the third storage device 12
They are stored in the storage device 13 and the fourth storage device 14, respectively. Next, the 16-bit block data stored in the first storage device 11 and the 1-bit block data stored in the third storage device 13
The 6-bit block data is input to the control device 20.
The control device 20 compares the magnitudes of the two input 16-bit block data. If the 16-bit block data stored in the first storage device 11 is larger or equal, the control signal is sent to the first data agitating device 31. 1 and a control signal 0 to the second data agitating device 32. Third storage device 13
If the 16-bit block data stored in the second data stirrer is larger, the control signal 1 is sent to the second data agitator 32,
The control signal 0 is sent to the data stirring device 31.

Next, the first data stirring device 31 is provided with 16-bit block data held in the first storage device 11, a control signal from the control device 20, and two for each number of repetition stages. That is, the 16-bit block key data at the beginning of the corresponding number of stages in the 16-bit block key data prepared in total of 16 sets of 8 sets,
K2i-1 shown in FIG. 1 (where i is the corresponding number of stages, i = 1, 2,..., 8) is input. In the first data stirring device 31, as shown in FIG. 3, the selection switch 220 is prepared according to the value of the control signal.
The stirring function device to be used is determined from the two stirring function devices. If the control signal is 0, the first stirring function device 211 is used for the stirring process, and if the control signal is 1, the second stirring function device 212 is used for the stirring process. Subsequently, the 16-bit block key data and the 16-bit block data held in the first storage device 11 are input to the agitation function device used for the agitation process determined by the above process, and the result of the agitation process performed Of the 16-bit block data of the first
The data is output as an output of the data stirring device 31.

The second data agitating device 32 is provided with 16-bit block data held in the third storage device 13, a control signal from the control device 20, and two for each number of repetition stages. That is, of the 16 sets of 16-bit block key data prepared in a total of 16 sets, the latter 16-bit block key data corresponding to the number of steps, K2i shown in FIG. 1 (where i is the number of corresponding steps) , I =
1, 2,..., 8) are input. In the second data stirring device 32, as shown in FIG.
0 determines the stirring function device to be used from the two prepared stirring function devices according to the value of the control signal. When the control signal is 0, the first stirring function device 211 is used for the stirring process, and when the control signal is 1, the second stirring function device 212 is used for the stirring process. Subsequently, the 16-bit block key data and the 16-bit data input from the third storage device 13 are input to the stirring function device used for the stirring process determined by the above process.
The 16-bit block data resulting from the input of the bit block data and the stirring process is output as the output of the second data stirring device 32.

Next, the output of the first data agitation device 31 and the data stored in the second storage device 12 are stored in the first arithmetic device 41.
6-bit block data is input. First arithmetic unit 4
At 1, the exclusive OR operation for each bit of the input two 16-bit block data is performed.
Outputs 6-bit block data. Further, the output of the second data stirring device 32 and the data stored in the fourth storage device 14 are input to the second arithmetic device 42. The second arithmetic unit 42 performs an exclusive OR operation for each bit of the input two 16-bit block data, and outputs the resulting 16-bit block data.

Finally, the data exchange device 50
The 16-bit block data stored in the storage device 11 is output as the second 16-bit block data from the left, and the 16-bit block data stored in the third storage device 13 is output as the fourth 16-bit block data from the left. Output from the first arithmetic unit 41
The bit block data is output as the third 16-bit block data from the left, and the 16-bit block data output from the second arithmetic unit 42 is output as the leftmost 16-bit block data. Data exchange device 50
The four 16-bit block data output by the above becomes the output data of the encryption processing device 120.

The above is the encryption processing in the single-stage encryption processing device 120. In the present embodiment, the encryption processing device 1
The processing by the encryption processing device 120 is repeated eight stages in such a manner that the output of 20 is used as the input of the encryption processing device 120 at the next stage. After the processing by the one-stage encryption processing device 120 is repeated eight stages as described above, the encryption processing device 120
Output from the repetition device 130.

As described above, according to the present embodiment, the control device 20 compares the 16-bit block data stored in the first storage device 11 with the 16-bit block data stored in the third storage device 13. Depending on the result, the first
A control signal is sent to the data stirrer 31 and the second data stirrer 32, and a stirrer function device used in the first data stirrer 31 and the second data stirrer 32 is determined based on the value of the control signal. Thus, for each of the eight stages of the encryption processing device 120 in the repetition device 130,
Different stirring processes can be performed. The manner in which the stirring function device is used in each stage, ie, the type of stirring process, is the same as the case where the first data stirring device 31 uses the first stirring function device 211 and the second data stirring device 32 uses the second stirring function 212. There are two types in which the first data stirring device 31 uses the second stirring function device 212 and the second data stirring device 32 uses the first stirring function 211.
There are combinations of power types. Therefore, even if the processing at each stage is analyzed to attempt to decrypt the data encryption device in the present embodiment, the probability of success is reduced as compared with the data encryption device in the conventional example.

Further, the data encryption device according to the present embodiment has a process in which the algorithm changes according to the values of the input data and the key data input to the data agitation device. Decryption becomes more difficult than in the case.

When three types of stirring function devices are prepared and the stirring function device is selected from among them,
Since the number of combinations of the stirring function devices in each stage, that is, the number of types of the stirring process is further increased, a further effect is obtained.

The input data is divided into eight block data, the configuration of the encryption processing device 120 is expanded from four columns to eight columns, four types of stirring function devices are prepared, and a stirring function device is selected from among them. It goes without saying that such a configuration produces further effects. Also, the number of bits of the input data is increased to 128 bits, and the unit of processing is 32.
The same effect is obtained when a device that converts the bits is configured. Further, needless to say, even if the repetition processing is performed 16 times, a further effect is produced.

In this embodiment, the comparison between the block data stored in the odd-numbered storage devices 11 and 13 indicates that the block data stored in each of the odd-numbered storage devices has been compared. Has a control device that outputs a control signal corresponding to each of the even-numbered storage units 12 and 14. According to the result of comparing the block data among the block data held in the even-numbered storage units 12 and 14, each of the even-numbered storage units A control device for outputting a control signal corresponding to the block data held in the storage device, wherein one block key data and one block of the block data held in the even-numbered storage device The data is input to the stirring function device selected by the corresponding control signal, and the stirring process is performed. The exclusive switch operation is performed by associating one of the block data held in the odd-numbered storage devices 11 and 13 with the output of the data stirrer, and an exclusive OR operation is performed to output the block data. And a data exchange device for exchanging the block data held in the odd-numbered storage device and the block data output from the arithmetic device in block units.

Next, FIG. 4 shows a configuration diagram of a second embodiment of the present invention. The configuration shown in FIG. 4 relates to the agitation processing unit, and the first data agitation device 31 and the second data agitation device 32 in the configuration diagram of the encryption processing device in the first embodiment shown in FIG. It replaces the configuration and function of. Other configurations and functions are the same as those of the first embodiment.

In FIG. 4, reference numeral 311 denotes a first agitation function device for inputting 16-bit block data and 16-bit block key data and outputting 16-bit block data obtained as a result of performing agitation processing, 312 denotes a 16-bit block A second agitation function device 321 that inputs data and 16-bit block key data and outputs a 16-bit block data resulting from the agitation processing has the same function as the selection switch 220 shown in FIG. The first selection switch 322 having the 16-bit block data stored in the first storage device 11 as input data has the same function as the selection switch 220 shown in FIG.
Is a second selection switch that uses the 16-bit block data stored in the memory as input data. The part of the operation of this embodiment different from that of the first embodiment will be described below.

The first selection switch 321 stores 16-bit block data stored in the first storage device 11,
6-bit block key data K2i-1 and control device 20
Is input, and processing is performed based on the value of the control signal. When the value of the control signal is 0, the first stirring function device 311 is set.
2, and sends the 16-bit block data and 16-bit block key data to the selected stirring function device. The selected agitation function device sends the 16-bit block data resulting from the agitation processing of the two input 16-bit data to the first selection switch 321. First selection switch 32
1 sends the 16-bit block data received from the stirring function device to the first arithmetic unit 41 as an output.

The second selection switch 312 has a third
The 16-bit block data and 16-bit block key data K2i stored in the storage device 13 and the control signal output from the control device 20 are input, and processing is performed according to the value of the control signal. When the value of the control signal is 0, the first agitation function device 311 is selected, and when it is 1, the second agitation function device 312 is selected, and the 16-bit block data and the 16-bit block key data are stored in the selected agitation function device. send. In the chosen stirring function device, the two 16
The 16-bit block data resulting from the agitation processing of the bit data is sent to the second selection switch 322. The second selection switch 322 sends the 16-bit block data received from the stirring function device to the second operation device 42 as an output.

Here, in the one-stage encryption process, when the control signal 1 is sent to the first selection switch 321, the control signal 0 is sent to the second selection switch 322.
When the control signal 0 is sent to the first selection switch 321, the second
Since 1 is sent to the selection switch 322, no data is sent from the first selection switch 321 and the second selection switch 322 to the same stirring function device at the same time. Therefore, the first
The processes of the selection switch 321 and the second selection switch 322 may be performed simultaneously.

According to the present embodiment, since the stirring function device can be shared, the data encryption device can be configured more simply.

[0034]

As described above, according to the present invention,
In a data encryption device that performs encryption by repeating the same process in multiple stages, the encryption process can be changed depending on the input data, and the effect is as if different processes were performed in each stage. Therefore, the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an encryption processing device of a data encryption device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a data encryption device in the embodiment.

FIG. 3 is a configuration diagram of a stirring processing device of the encryption processing device in the embodiment.

FIG. 4 is a configuration diagram of a stirring processing device of an encryption processing device according to a second embodiment of the present invention;

FIG. 5 is a configuration diagram of a conventional data encryption device.

[Explanation of symbols]

 Reference Signs List 11 first storage device 12 second storage device 13 third storage device 14 fourth storage device 20 control device 31 first data stirring device 32 second data stirring device 41 first computing device 42 second computing device 50 data exchange device 110 Input data processing device 120 Encryption processing device 130 Repetition device 140 Output data processing device 211 First stirring function device 212 Second stirring function device 220 Selection switch 311 First stirring function device 312 Second stirring function device 321 First selection switch 322 Second selection switch

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironori Murakami 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-4-365240 (JP, A) Zheng, T .; Matsumo to, H .; Imai, "On the Construction of Block Ciphers Probably Secure and Not Relying on Any Unprovisioned Hypotheses," Lecture Notes Certificate. 435, (1990), p. 461-480 (58) Fields investigated (Int. Cl. ⁶ , DB name) G09C 1/00-5/00 H04K 1/00-3/00 H04L 9/00-9/38 JICST file (JOIS) INSPEC ( DIALOG)

Claims (6)

(57) [Claims] 1. An even number of equal lengths stored in a storage device.
The block data is processed and the block data is processed.
Block data that is half the number of block data
Data as well as the other half blocks
Select the data as block data to be agitated, and
The agitation processing determined by the value of the block data
In addition, the agitation block data is used to control key data.
And the result of stirring by the stirring function described above.
Exclusive OR between the block data to be mixed and
The result of performing the exclusive OR operation
Block data and all the agitation block data
After replacing data in block units
The block data is digitized, and the randomized block
Block data as block data to be processed.
All the processes described above are repeated a plurality of times, and the
The randomized block data after repetition
In the storage device as encrypted block data
A data encryption method. 2. An even number of equal lengths stored in a storage device.
Perform different processing on block data
Prepare a plurality of stirring functions, and
Block data that mixes half of the block data
Data as well as the other half of the block data
Data is selected as block data for stirring,
One of the stirring functions based on the value of the block data
And select the block data to be stirred
Stirring under the control of key data using the stirring function
The result of stirring by the stirring function and the stirring
Exclusive OR operation with the block data
The block data resulting from the exclusive OR operation.
Data and all the block data to be agitated
Randomized after replacing data in units
The block data, and the randomized block data
Are all described above as block data to be processed.
Is performed a plurality of times, and the above-described plurality of times is repeated.
After performing, the randomized block data is encrypted.
To be stored in the storage device as
The data encryption method according to claim 1 , wherein: 3. An even number of equal-length block data stored in a storage device is processed, and a plurality of stirring functions for performing different processes are prepared. At the same time as selecting the block data to be agitated, the remaining half of the block data is selected as the block data to be agitated, and one of the block data to be agitated corresponds to one of the block data to be agitated. A process of combining a set of block data is performed on all the block data without duplication to form a combination of a plurality of block data, and the agitation function is performed in accordance with a plurality of values of the agitation block data. The process of associating one of the above with one of the stirring block data is performed on all the stirring block data. The block data to be agitated in each block data combination is agitated under the control of key data by the corresponding agitation function, and the agitation function is used in each block data combination by the agitation function. The exclusive OR operation is performed between the result of the agitation and the block data to be agitated, and the block data of the result of the exclusive OR operation performed on all the combinations of the block data and all the agitation are performed. After replacing the data in block units with the block data, the block data is converted into randomized block data.
The randomized block data is used as block data to be processed.All the processes described above are repeated a plurality of times, and the randomized block data after performing the plurality of repetitions is an encrypted block. Data and
And storing the data in a storage device . 4. Each of a plurality of block data is held.
An even number of storage devices and an odd (even) number of the storage devices
The block data and block key data held in
Input and agitation determined by the value of the block data
Performs processing and outputs the resulting block data.
Data stirrer and stored in even (odd) number storage devices
Block data and the output of the data stirrer
Performs exclusive OR operation on and outputs block data
And an odd (even) number storage device.
Block data and output from the arithmetic unit
Swaps block data with block data
Equipped with an encryption processor consisting of a data exchange device
The processing by the encryption processing device is repeated a predetermined number of times.
Data encryption device. 5. The data stirring device according to claim 1, wherein
And block key data to perform agitation
Multiple stirrer function devices that output data and odd (even) numbers
Of the block data held in the storage device
A control device that outputs a control signal according to the
Data and odd (even) number stored in the storage device
Block data is selected by the corresponding control signal.
Input to the stirring function device to perform a stirring process,
And a selection switch that outputs the resulting block data.
5. The data encryption according to claim 4, wherein the data encryption is performed.
apparatus. 6. An even number of storage devices each holding a plurality of block data, a plurality of agitation function devices for inputting block data and block key data, performing agitation processing and outputting block data, and an odd ( even ) device. As a result of comparing two or more block data of the block data held in the storage device of the number, the block data corresponding to each of the odd ( even ) number storage devices is determined. A control device that outputs a control signal, one block key data and one block data among the odd ( even ) number block data held in the storage device are selected by the corresponding control signal. A selection switch for inputting the data to the stirring function device to perform the stirring process and outputting the resulting block data, and storing the data in an even-numbered storage device One of the block data being processed and the output of the data agitation device correspond to each other to perform an exclusive OR operation and output the block data; and an odd ( even ) number storage device. An encryption processing device including a data exchange device for exchanging the held block data and the block data output from the arithmetic device in block units, and performing a predetermined process by the encryption processing device; A data encryption device that repeats a number of times.