JP4920297B2 - Encryption / decryption method and apparatus - Google Patents

Description

  The present invention relates to an encryption / decryption method and apparatus that can easily cope with various algorithms and that can switch algorithms at high speed.

  Since the encryption / decryption process is generally a heavy load process, it is widely practiced to install a hardware encryption processing unit in equipment used for encrypted communication for the purpose of speeding up the process. Therefore, conventionally, only a predetermined algorithm can be handled, and it is difficult to deal with various algorithms.

In order to solve such a problem, an encryption algorithm is determined according to information on the destination at the time of packet transmission and the transmission source at the time of packet reception, and an attempt to support various encryption algorithms by configuring a reconfigurable circuit In addition, attempts have been made to cope with various algorithms by transmitting / receiving circuit configuration data corresponding to an encryption algorithm and setting the data in a reconfigurable circuit (see, for example, Patent Document 1).
JP 2003-198530 A

In conventional encryption / decryption methods and devices, the encryption algorithm is determined based on the information obtained from the transmission / reception packet, and the reconfigurable circuit is reconfigured from that point, or the circuit configuration data itself is transmitted / received. Since the circuit is reconfigured by setting the data, there is a problem that it takes time to switch the algorithm.
In addition, if multiple reconfigurable circuits are installed, the circuit that has not been executed is reconfigured in advance, and the switch is made so that it is executed when necessary, the time required for switching to a different algorithm can be shortened. However, since a plurality of reconfigurable circuits are required, there is a problem that the cost is increased.

  The present invention has been made in order to solve the above-described problems, and can be easily applied to various algorithms, and can perform encryption / decryption processing algorithm switching at high speed and at low cost. It is an object of the present invention to obtain a method and an apparatus therefor.

The encryption / decryption method according to the present invention includes:
In a method of performing encryption / decryption with a different circuit configuration for each predetermined process using a circuit device capable of dynamically changing a circuit configuration,
Configuring the circuit of the circuit device using circuit configuration data for performing encryption / decryption processing used when performing the first processing;
A prediction step of predicting a start timing of the second process based on whether or not the instruction pattern of the handshake process is an end process of the handshake process ;
Based on the result of the prediction step, prior to the timing at which the second process is predicted to start, using circuit configuration data for performing the encryption / decryption process used when performing the second process, A circuit configuration step for configuring a circuit of the circuit device;
It is characterized by having.

Further, the encryption / decryption device according to the present invention includes:
Control means;
A circuit device capable of dynamically changing a circuit configuration is provided, and an encryption / decryption process is performed with a different circuit configuration for each predetermined process executed by the control unit using the circuit device based on an instruction from the control unit Encryption / decryption means for performing
Storage means for storing a plurality of types of circuit configuration data;
Have
The control means includes
Read the circuit configuration data for performing encryption / decryption processing used when performing the first processing from the storage means, and configure the circuit of the circuit device,
Predicting the start timing of the second process based on whether the instruction pattern of the handshake process is the end process of the handshake process ;
Based on the prediction result,
Prior to the timing at which the second process is predicted to start, the circuit device reads circuit configuration data for performing the encryption / decryption process used when performing the second process from the storage unit. The circuit is configured as follows.

According to the encryption / decryption method and apparatus according to the present invention,
Predict the future processing contents and the timing when the processing is executed, and rewrite the circuit configuration data of the encryption / decryption execution unit by the control means based on the prediction result. Circuit configuration data is set in a timely manner, and the algorithm switching process can be speeded up.
In addition, since it is not necessary to have a plurality of encryption / decryption means capable of rewriting circuit configuration data, an inexpensive configuration can be achieved.

Embodiment 1 FIG.
FIG. 1 is an overall configuration diagram of an encryption / decryption device that realizes an encryption / decryption method according to Embodiment 1 of the present invention.
In FIG. 1, a solid line frame indicates hardware, and a broken line frame indicates software or data. An alternate long and short dash line indicates the entire encryption / decryption device.
The encryption / decryption device 100 includes a microcomputer 101, an encryption / decryption execution unit 102, and a memory B103.
The encryption / decryption execution unit 102 includes, as hardware, a memory A 110 and a memory C 108 that store circuit configuration data, and an arithmetic processing unit 112 that configures a circuit based on the circuit configuration data stored in the memory C 108. It is included.
The memory C108 stores circuit configuration data 109 for performing the current operation of the encryption / decryption execution unit 102.
The memory A110 stores circuit configuration data A111 for the encryption / decryption execution unit 102 to perform the first operation.
The arithmetic processing unit 112 is a circuit device whose circuit configuration can be dynamically changed, and can be realized by a circuit device such as a CPLD (Complex Programmable Logic Device), for example.
The memory B103 stores circuit configuration data B104 for the encryption / decryption execution unit 102 to perform the second operation, and software M105.
The software M105 defines the operation of the microcomputer 101, and is read by the microcomputer 101 and the processing content is executed. The software M105 includes a process prediction module 106 and a control module 107.
The microcomputer 101 and the memory C108 are connected by a control line 113.
The microcomputer 101 and the memory B103 are connected by a control line 114.
The microcomputer 101 and the arithmetic processing unit 112 are connected by a control line 115.
The memory A110 and the memory C108 are connected by a control line 116.
The arithmetic processing unit 112 and the memory C108 are connected by a control line 117.
The arithmetic processing unit 112 and the memory A 110 are connected by a control line 118.
An external device 200 exists outside the encryption / decryption device 100, and both are connected by a communication path 201.

The “control means” in the present invention corresponds to the microcomputer 101 in FIG.
The “storage means” corresponds to the memory A110, the memory C108, and the memory B103 in FIG.
The “encryption / decryption means” corresponds to the encryption / decryption execution unit 102 in FIG.

The operation of the encryption / decryption execution unit 102 is defined by the contents of the circuit configuration data C109 set in the memory C108. That is, it is reconfigured by changing the contents of the circuit configuration data C109, and the operation changes.
This is because the arithmetic processing unit 112 dynamically changes the circuit configuration based on the contents of the circuit configuration data C109 set in the memory C108.

FIG. 2 illustrates how the circuit configuration data stored in the memory C108 is changed in accordance with the processing contents of the microcomputer 101.
(1)
In the initial state, circuit configuration data as shown in FIG. 1 is stored in the memory B103, the memory C108, and the memory A110.
(2)
When the microcomputer 101 performs a certain process (hereinafter referred to as a “first process” and corresponds to the “first process” in claim 1), the microcomputer 101 performs an encryption / decryption process corresponding to this process. Execution is performed by the conversion execution unit 102.
At this time, the microcomputer 101 reads the control module 107 included in the software M105, and loads the circuit configuration data A111 into the memory C108 to the arithmetic processing unit 112 of the encryption / decryption execution unit 102 using the control line 115. The control signal is transmitted.
Upon receiving the control signal, the arithmetic processing unit 112 loads the circuit configuration data A111 stored in the memory A110 into the memory C108, and replaces the circuit configuration data C109 with the circuit configuration data A111.
Thereafter, the arithmetic processing unit 112 operates according to the circuit configuration data set in the memory C108.
In this way, the encryption / decryption execution unit 102 performs encryption / decryption processing corresponding to the first processing of the microcomputer 101.
(3)
Next, when the microcomputer 101 performs another process (hereinafter referred to as a second process, which corresponds to the “second process” in claim 1) following the first process, it corresponds to this. The encryption / decryption processing unit 102 is caused to execute encryption / decryption processing.
At this time, the microcomputer 101 reads the control module 107 included in the software M105, loads the circuit configuration data B104 stored in the memory B103 into the memory C108 of the encryption / decryption execution unit 102 via the microcomputer 101, The circuit configuration data C109 is replaced with circuit configuration data B104.
Thereafter, the arithmetic processing unit 112 operates in accordance with the circuit configuration data B104 set in the memory C108.
In this way, the encryption / decryption execution unit 102 performs encryption / decryption processing corresponding to the second processing of the microcomputer 101.

FIG. 3 illustrates encrypted communication as a specific example when it is necessary to dynamically change the circuit configuration of the arithmetic processing unit 112.
In general, when the confidentiality of communication contents is desired to be maintained by encrypted communication, it is desirable to encrypt the communication contents using a stronger encryption method. For example, if the communication content is encrypted using a public key cryptosystem, the strength of the encryption is increased as compared with the case where a secret key cryptosystem is used.
However, in order to perform encryption / decryption processing using a public key cryptosystem, a relatively large calculation capability is required. Therefore, when the processing capability of the calculation device is limited, the two are combined. A method may be used.
(1)
First, on the communication content transmission side, the secret key is encrypted by a public key cryptosystem, and the encrypted secret key is transmitted to the reception side in advance.
In the upper diagram of FIG. 3, the public key encryption circuit 301 receives the private encryption key P1 before encryption, the public key e, and the modulus m as inputs, and outputs the encrypted private encryption key c1.
The secret encryption key c1 is transmitted in advance to the communication content receiving side (not shown), and the receiving side decrypts the secret encryption key c1.
(2)
Next, when transmitting the communication content, the communication content is encrypted using the secret key corresponding to the secret key transmitted to the receiving side in step (1), and then transmitted to the receiving side.
In the lower part of FIG. 3, the secret key encryption circuit 302 receives the transmission text P2 before encryption as an input, and outputs the transmission text c2 after encryption.
On the receiving side, the communication contents are decrypted using the secret encryption key c1 received in step (1).

As described above, different encryption methods may be used in one communication process. This is not limited to communication, and similar cases exist in various processes for performing encryption.
As shown in FIG. 3, if different circuits are used for each encryption method, it is disadvantageous in terms of cost and the like, and it is desirable that a single circuit can handle both encryption methods.
In addition, when a circuit in which both encryption / decryption algorithms are simply used is used, the device size may increase due to the limitation on the number of gates of the circuit device.
Therefore, the encryption / decryption device according to the present invention pre-reads the timing at which the encryption method must be switched and switches the circuit configuration in advance, so that the circuit configuration switching waiting time can be achieved with a single circuit device. A plurality of encryption schemes are supported without causing any problems.

Next, an operation when the encryption / decryption device 100 in FIG. 1 performs encrypted communication with the external device 200 via the communication path 201 will be described.
The encryption / decryption device 100 is connected to an external device 200 that is a counterpart of encrypted communication via a communication path 201. This communication path 201 is a logical communication path, and it does not matter whether it is wired or wireless.
Further, the encryption / decryption device 100 includes an external device communication unit (not shown) for communication with an external device. The external device communication unit may be configured as a component separate from the microcomputer, or may be incorporated in the microcomputer.
Here, it is assumed that the circuit configuration data A111 for performing the first operation of the encryption / decryption executing unit 102 is circuit configuration data for performing the encryption / decryption operation for the communication handshake protocol.
Further, the circuit configuration data B104 for performing the second operation is set as circuit configuration data for performing the encryption / decryption operation for communication application data.
As for the communication procedure, it is assumed that application data is transmitted / received after handshaking to establish a communication path with the communication partner, and different encryption algorithms are used in each phase of handshaking, transmission / reception of application data. Shall.

  FIG. 4 illustrates an operation flowchart when the encryption / decryption device 100 of FIG. 1 performs encrypted communication with the external device 200 via the communication path 201. Hereinafter, each step will be described.

(S401)
When performing communication, the handshake is always performed first, and therefore the encryption / decryption execution unit 102 needs to operate the encryption algorithm for the handshake protocol first.
Therefore, first, circuit configuration data for performing an operation for the handshake protocol is set in the memory C108. That is, the microcomputer 101 loads the circuit configuration data A111 into the memory C108 based on the instruction content of the control module 107.
(S402)
When communication is started and handshake is started, the microcomputer 101 prefetches the next processing block of the execution software M105 of the microcomputer based on the instruction content of the processing prediction module 106, and temporarily stores the instruction pattern.
(S403)
The microcomputer 101 determines whether or not the prefetched instruction pattern is the handshake completion pattern by comparing the prestored instruction pattern when the handshake is completed with the temporarily stored prefetched instruction pattern. This means that it is determined whether or not the end of the handshake process is approaching.
(S404)
If the instruction pattern prefetched in step S402 is not a handshake completion pattern, the microcomputer 101 continues prefetching of the process of the software M105 as the communication handshake process proceeds.
If it is determined that the handshake completion pattern is reached, the elapsed time from that point is started.
(S405)
The microcomputer 101 waits for the algorithm switching start prediction time to elapse.
Here, the predicted algorithm switching start time is “standard time from prefetching a handshake completion command pattern to completion of actual handshake processing” − “time required for algorithm switching (= circuit configuration data B104 is stored in memory C108) The time required for loading to “)”.
(S406)
When the microcomputer 101 confirms that the algorithm switching start prediction time has elapsed, it sets circuit configuration data for performing the operation for application data in the memory C108. That is, the microcomputer 101 loads the circuit configuration data B104 into the memory C108 based on the instruction content of the control module 107.
Thereafter, application data encryption communication is performed using the encryption / decryption execution unit 102 on which the encryption algorithm for application data operates.

FIG. 5 is a sequence diagram for explaining the relationship between the flowchart shown in FIG. 4 and the elapsed time in actual communication processing with the elapsed time axis set on the vertical axis.
The flowchart shown in the right half of FIG. 5 is the flowchart of FIG.
The microcomputer 101 performs overall operation control when the encryption / decryption device 100 in FIG. 1 performs encrypted communication with the external device 200. Hereinafter, the relationship between steps S501 to S503 and the elapsed time will be described.
(S501)
In step S401, the microcomputer 101 starts handshaking with the external device 200 after circuit configuration data for handshaking processing is set in the memory C108.
(S502)
Before the handshake with the external device 200 is completed, it is necessary to prepare so that an encryption process used for application data transmission after the handshake is completed can be performed.
That is, it is necessary to set the circuit configuration data in the memory C108 in advance in consideration of the time required for step S406.
(S503)
The microcomputer 101 starts processing for transmitting application data after the handshake is completed. That is, after the handshake as the preprocessing is completed, the process proceeds to a step of transmitting the communication data body.
The data transmitted to the external device at this time is the data after the encryption processing is performed using the circuit configuration data set in the memory C108 in step S406.

In the first embodiment, the memory B103 is described as being externally attached to the microcomputer, but may be realized by a memory built in the microcomputer. Further, the data B104 and the software M105 stored in the memory B103 may be stored in areas of different address ranges in the same physical memory as illustrated in FIG. They may be arranged on physically different memories.
In particular, with the latter configuration, even if the memory is a FLASH memory, the data B104 can be rewritten while the software M105 is being executed by the microcomputer 101, and the processing contents of the encryption / decryption execution unit 102 can be more freely and dynamically performed. There is also a merit that it becomes possible to change.
Further, although the memory A110 and the memory C108 have been described as physically different memories, they may be physically different areas of the same memory.
Further, here, the encryption / decryption execution unit 102 has been described as being implemented by switching two different algorithms, but may be implemented by switching between three or more algorithms.
At that time, the capacity of each of the memory A110, the memory B103, and the memory C108, and the circuit configuration data that realizes which algorithm is stored in which area of which memory can be freely determined. If an optimum design is performed according to the system, Good. In addition, as for the prediction method, the method shown here is merely an example, and other prediction methods may be used.

As described above, according to the first embodiment,
Predict the timing to switch the circuit configuration data, and read the necessary circuit configuration data into the memory in advance,
Optimal circuit configuration data corresponding to the progress of the process is set with good timing, and the algorithm switching process can be speeded up.
In addition, since a single reconfigurable encryption / decryption execution unit 102 can provide a sufficiently high speed performance, it can be realized at a lower cost than a configuration in which a plurality of reconfigurable encryption / decryption execution units 102 are required.

In addition, the process contents after the process currently being executed in the first process are read in advance before the execution of the process, and the process contents read in advance include the contents of the end process of the first process. If the standard time required until the end of the first process has elapsed since the pre-reading time, it is predicted that the start timing of the second process,
Optimal circuit configuration data can be set at an appropriate timing.

In addition, the circuit configuration required for performing the second process at a timing obtained by subtracting the time required for the circuit configuration used for performing the second process from the timing at which the second process is predicted to start. So start
It is possible to avoid the situation in which the first process ends during switching of the circuit configuration and a waiting time occurs, and the entire process including the switching of the algorithm can be performed efficiently.

Embodiment 2. FIG.
FIG. 6 is an overall configuration diagram of an encryption / decryption device that realizes the encryption / decryption method according to Embodiment 2 of the present invention.
In the second embodiment, the learning module 120 is provided in the software M105 that defines the operation of the microcomputer 101.
The learning module 120 prescribes a learning process in which the switching timing of the circuit configuration data is recorded in a memory a predetermined number of times or for a predetermined time, and the switching timing after the next time is corrected based on the contents. The microcomputer 101 performs the learning process based on the instruction content of the learning module 120.
Other configurations are the same as those in FIG. 1 in the first embodiment, and a description thereof will be omitted.

Next, the learning process of the microcomputer 101 based on the learning module 120 will be described.
(1)
Based on the instruction contents of the learning module 120, the microcomputer 101 calculates the sum of squares of the error of the algorithm switching start prediction time, that is, “algorithm switching start prediction time” − “actual switching required every time the algorithm needs to be switched”. Find the sum of squares.
(2)
The microcomputer 101 provides a certain unit time or unit number based on the instruction content of the learning module 120 and continuously accumulates the sum of squares obtained in step (1).
(3)
Based on the instruction content of the learning module 120, the microcomputer 101 determines that “from prefetching the handshake completion command pattern to completion of the actual handshake process so that the integrated value obtained in step (2) is minimized. The algorithm switching start prediction time is dynamically adjusted by adjusting the “standard time”.

The learning process of the algorithm switching timing of the microcomputer 101 may be performed by providing a predetermined storage area in, for example, the memory B103 in FIG.
Although it may be stored in the memory A110 or the memory C108, since the learning process is related to the microcomputer 101, it is more convenient in processing to store it in the memory B103 in which the software M105 is stored.

In order to prevent the switching of the algorithm, that is, the error in the timing of starting rewriting of the circuit configuration data as much as possible, at the beginning of the learning, the rewriting is started with a margin of time, and the learning is gradually optimized. Rewriting may be started at the timing.
In this case, at the beginning of learning, for example, a time obtained by adding a certain time to the algorithm switching start prediction time predicted by the processing prediction module 106 is regarded as the algorithm switching start prediction time, and for example, certain fixed time. This can be realized by adjusting the algorithm switching start prediction time using the learning result when the learning progresses, such as learning the number of times.

  Similarly, in order to prevent the switching of the algorithm, that is, the error in the timing of starting rewriting of the circuit configuration data as much as possible, the processing completion notification of the algorithm currently being processed is sent from the encryption / decryption execution unit 102 to the microcomputer 101. Notification is made through the control line 115, and at the beginning of learning, the process predicting means receives the process completion notification as a trigger to start algorithm switching, that is, rewriting of circuit configuration data, and learning progressed. The learning switching result may be used to adjust the algorithm switching start prediction time.

In this way, it is possible to learn and dynamically adjust the algorithm switching timing, that is, the timing to start rewriting circuit configuration data, so that it follows the communication environment, the communication partner, and their temporal changes. Therefore, it is possible to always maintain the optimum circuit configuration data change timing.
Note that the learning method of the learning means is merely an example, and other learning methods may be used.

As described above, according to the second embodiment,
A predetermined number of differences between the prediction result of the start timing of the second process and the actual start timing of the second process are stored in the memory;
Since the next prediction result of the start timing of the second process is corrected so that the difference between the two timings becomes small,
It is possible to always keep the optimum circuit configuration data change timing following the communication environment, the communication partner, and their temporal changes.

When predicting the start timing of the second process,
Since the square sum of the difference between the start timing prediction result of the second process stored in the memory and the actual start timing is obtained and the next prediction result is corrected so that the square sum is minimized,
A generally established optimization method such as a least square method can be used, and the prediction accuracy of the timing for switching the circuit configuration is improved.

Further, when predicting the start timing of the second process, a predetermined margin time is added to determine the next prediction result,
Each time the prediction result is corrected next time, the margin time is increased or decreased.
It is possible to reduce the possibility of an error in timing of algorithm switching, that is, rewriting start of circuit configuration data.

In addition, until the second process is executed a predetermined number of times,
Since the start timing of the second process is skipped and the configuration of the circuit used when the second process is performed after the first process is completed,
Using inaccurate prediction timing in the initial stage of learning, it is possible to prevent the algorithm from being switched at the wrong timing, that is, rewriting the circuit configuration data.

Embodiment 3 FIG.
FIG. 7 is an overall configuration diagram of an encryption / decryption device that realizes the encryption / decryption method according to Embodiment 3 of the present invention.
The encryption / decryption device 100 in FIG. 7 includes a memory B103 and a memory D119.
The memory B103 stores circuit configuration data B104 for the encryption / decryption execution unit 102 to perform the second operation.
The memory D119 stores software M105 that defines the operation of the microcomputer 101.
The software M105 includes a process prediction module 106, a control module 107, and a communication module 122.
The communication module 122 is software that realizes a function for the microcomputer 101 to exchange data with a device external to the encryption / decryption apparatus 100, such as the external device 200 in FIG.
The arithmetic processing unit 112 and the memory D119 are connected by a control line 121.
Moreover, it is the same as that of Embodiment 1 to provide the external apparatus communication part (not shown) normally used for communication with an external apparatus.
Other configurations are the same as those in FIG. 1 in the first embodiment, and a description thereof will be omitted.

The microcomputer 101 acquires the circuit configuration data of the encryption / decryption execution unit 102 from the external device according to the instruction content of the communication module 122, and the circuit configuration data is the same as when the circuit configuration data B104 is set in the memory C108. Through the process, the memory C108 is set.
As a result, the encryption / decryption executing unit 102 can be operated with a new algorithm that is not currently held by the encryption / decryption device 100.
The circuit configuration data acquired from the external device in accordance with the instruction content of the communication module 122 may be directly loaded into the memory C108, or may be temporarily stored in the memory B103 or other memory area.
It is also possible to accept a request by receiving a command from an external device through communication, etc., rewrite the circuit configuration data of the encryption / decryption execution unit 102, and change the function.

7 differs from the configuration shown in FIGS. 1 and 6 in that the memory B103 that stores the circuit configuration data B104 and the memory D119 that stores the software M105 that defines the operation of the microcomputer 101 are separated. .
This is because the data B104 can be rewritten during execution of the software M105 even if the memory B103 and the memory D119 are configured using a device such as a type of FLASH memory that cannot be read during the writing process. It is an example for.
The configuration of the memory in the third embodiment is not limited to this, and it may be a form that is physically stored in the same memory as in FIG.

  Up to this point, the description has been made for all the encryption / decryption devices, but the same applies to the encryption / decryption methods implemented by each. Furthermore, although Embodiment 1, 2, and 3 were demonstrated, these may be used individually or may be used combining arbitrary forms, respectively, and what is necessary is just to build the most effective structure according to an application object.

As described above, according to the third embodiment,
Since it has a communication means for acquiring circuit configuration data via a network,
It is possible to dynamically change the function to more various algorithms. If wide-area communication is applied to communication with the outside, it is possible to change the function of the encryption / decryption execution unit from a remote location. Furthermore, since the circuit configuration data can be rewritten from the outside, the flexibility of rewriting the circuit configuration data is increased, and rewriting can be performed at times other than the predicted timing.

1 is an overall configuration diagram of an encryption / decryption device that realizes an encryption / decryption method according to Embodiment 1. FIG. The manner in which the circuit configuration data stored in the memory C108 is changed according to the processing contents of the microcomputer 101 will be described. As a specific example when the circuit configuration of the arithmetic processing unit 112 needs to be dynamically changed, encrypted communication will be described as an example. An operation flowchart when the encryption / decryption apparatus 100 in FIG. 1 performs encrypted communication with the external device 200 via the communication path 201 will be described. FIG. 5 is a sequence diagram for explaining the relationship between the flowchart shown in FIG. 4 and the elapsed time in actual communication processing by setting the elapsed time axis on the vertical axis. FIG. 5 is an overall configuration diagram of an encryption / decryption device that realizes an encryption / decryption method according to a second embodiment. FIG. 9 is an overall configuration diagram of an encryption / decryption device that realizes an encryption / decryption method according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Encryption / decryption apparatus, 101 Microcomputer, 102 Encryption / decryption execution part, 103 Memory B, 104 Circuit configuration data B, 105 Software M, 106 Process prediction module, 107 Control module, 108 Memory C, 109 Circuit configuration Data, 110 Memory A, 111 Circuit configuration data A, 112 Operation processing unit, 113 Control line, 114 Control line, 115 Control line, 116 Control line, 117 Control line, 118 Control line, 119 Memory D, 120 Learning module, 121 Control line, 122 communication module, 200 external device, 201 communication path, 301 public key encryption circuit, 302 secret key encryption circuit.

Claims (16)

In a method of performing encryption / decryption with a different circuit configuration for each predetermined process using a circuit device capable of dynamically changing a circuit configuration,
Configuring the circuit of the circuit device using circuit configuration data for performing encryption / decryption processing used when performing the first processing;
A prediction step of predicting a start timing of the second process based on whether or not the instruction pattern of the handshake process is an end process of the handshake process ;
Based on the result of the prediction step, prior to the timing at which the second process is predicted to start, using circuit configuration data for performing the encryption / decryption process used when performing the second process, A circuit configuration step for configuring a circuit of the circuit device;
And an encryption / decryption method. In the prediction step,
The processing content after the currently executing process in the first process is read in advance before executing the process after the currently executing process,
When the processing content read in advance includes the content of the end processing of the first processing,
2. The encryption / decoding according to claim 1, wherein a point in time at which a standard time required for the end of the first process has elapsed since the pre-reading point is predicted to be a start timing of the second process. Decryption method.   3. The execution of the circuit configuration step is started at a timing obtained by subtracting a time required for the circuit configuration step from a timing at which the second process is predicted to start in the prediction step. The encryption / decryption method described. A storage means for storing a predetermined number of prediction results in the prediction step and an actual start timing of the second process;
The encryption / decryption method according to any one of claims 1 to 3, further comprising a learning step of correcting a next prediction result of the prediction step so that a difference between both timings becomes small. In the learning step,
Finding the sum of squares of the difference between the prediction result and the actual start timing stored in the storage means, and correcting the next prediction result of the prediction step so that the square sum is minimized. The encryption / decryption method according to claim 4. In the learning step, a predetermined margin time is added to determine the next prediction result,
6. The encryption / decryption method according to claim 4, wherein the margin time is increased or decreased each time the learning step is repeated. Until the second process is executed a predetermined number of times,
7. The encryption / decryption according to claim 4, wherein the prediction step and the learning step are skipped, and the circuit configuration step is started after the first processing is completed. Method.   8. The encryption / decryption method according to claim 1, further comprising a step of acquiring the circuit configuration data via a network. Control means;
A circuit device capable of dynamically changing a circuit configuration is provided, and an encryption / decryption process is performed with a different circuit configuration for each predetermined process executed by the control unit using the circuit device based on an instruction from the control unit Encryption / decryption means for performing
Storage means for storing a plurality of types of circuit configuration data;
Have
The control means includes
Read the circuit configuration data for performing encryption / decryption processing used when performing the first processing from the storage means, and configure the circuit of the circuit device,
Predicting the start timing of the second process based on whether the instruction pattern of the handshake process is the end process of the handshake process ;
Based on the prediction result,
Prior to the timing at which the second process is predicted to start, the circuit device reads circuit configuration data for performing the encryption / decryption process used when performing the second process from the storage unit. An encryption / decryption device comprising the circuit of The control means includes
When predicting the start timing of the second process, the process contents after the process currently being executed in the first process are read in advance before executing the process after the process currently being executed. ,
When the processing content read in advance includes the content of the end processing of the first processing,
10. The encryption / decoding according to claim 9, wherein a point in time at which a standard time required for the end of the first process has elapsed from the pre-reading point is predicted to be a start timing of the second process. Decryption device. The control means includes
At a timing obtained by subtracting the time required for the circuit configuration used when performing the second processing from the timing at which the second processing is predicted to start,
11. The encryption / decryption device according to claim 10, wherein the circuit configuration is started. The storage means
Storing a predetermined number of differences between the prediction result of the start timing of the second process and the actual start timing of the second process;
The control means includes
12. The encryption / decryption device according to claim 9, wherein a next prediction result of a start timing of the second process is corrected so that a difference between both timings becomes small. . The control means includes
When predicting the start timing of the second process,
The sum of squares of the difference between the prediction result and the actual start timing stored in the storage means is obtained, and the next prediction result is corrected so that the square sum is minimized. The encryption / decryption device described in 1. The control means includes
When predicting the start timing of the second process, a predetermined margin time is added to determine the next prediction result,
14. The encryption / decryption device according to claim 12 or 13, wherein the margin time is increased / decreased every time correction of the next prediction result is repeated. The control means includes
Until the second process is executed a predetermined number of times,
15. The circuit configuration used when performing the second process is started after skipping the start timing of the second process and completing the first process. The encryption / decryption device according to any one of the above.   The encryption / decryption device according to any one of claims 9 to 15, further comprising communication means for acquiring the circuit configuration data via a network.

Images