JP4895068B2 - Processing apparatus and processing method - Google Patents

Description

  The present invention relates to a processing apparatus and a processing method for generating integrated data that includes encrypted data and can be decrypted by applying a predetermined operation.

  Encrypting the encrypted data is performed in the distribution of contents and the distribution of the program only when the data is encrypted and included in the integrated data, and the data is required.

  For example, in content distribution, the content is encrypted and distributed for copyright protection, and the encrypted content is decrypted and held only while the content is played back. Also, in the distribution of a program, only a person who has the title can execute the program, so various protection means are used, but in order not to break the protection means, the program is encrypted. Distribution and decryption of the encrypted program at the time of execution is performed. For example, Chapter 5 of Non-Patent Document 1 introduces freeware that encrypts a program, decrypts the program at the time of execution, and generates a program that executes the program.

FIG. 15 illustrates a state in which a program that is data is encrypted by the above-described freeware. The generated program 1501 includes a decryption function 1502 and encrypted data 1503. When the program 1501 is executed, the decryption function 1502 is applied to the encrypted data 1503 to decrypt the encrypted data and obtain data.
Pavol ▲ C ▼ erve ▲ n ▼ "CRACKPROOF YOUR SOFTWARE", NO STAR PRESS, USA, 2002

  When a program or the like is encrypted in the format illustrated in FIG. 15, for example, the operation of the decryption function is easily analyzed by disassembling the decryption function 1502. Accordingly, there is a problem that the encrypted data is easily decrypted by taking out the encrypted data portion and performing decryption based on the analysis result.

  Therefore, an object of the present invention is to provide a processing device that generates a program or the like that prevents encrypted data from being easily decrypted.

  In order to solve such a problem, the processing device provided by the present invention acquires data, acquires an encryption function for encrypting the acquired data, encrypts the data by encrypting the data with the encryption function Generate the data and also obtain the decryption function for decrypting the encrypted data, and based on the encrypted data and the decryption function, the integrated data that does not include the information indicating the decryption function directly Generate. It is assumed that the integrated data is configured so that a decryption function and encrypted data can be acquired by performing a predetermined operation.

  Since the integrated data generated by such a processing device does not directly include the decoding function, the decoding function is not analyzed and the problem is solved.

  Note that the encryption function for encrypting the acquired data may be such that the sizes of the data before encryption and after encryption are equal. As a result, the encrypted data included in the integrated data can be replaced with data obtained by decryption, and the possibility that the data obtained by decryption is separately recorded on a hard disk or the like is reduced.

  Further, the decryption function may be encrypted.

  Further, the encryption of the decryption function may be performed such that the size is the same before and after the encryption.

  Further, the decryption function and the data obtained by decryption may be held only in the main memory of the computer.

  The data encrypted by the encryption function may be a program, and the integrated data is a program that acquires the decryption function, applies the decryption function to the encrypted data, and executes the obtained data It may be.

  According to the present invention, since the decryption function is not directly included in the generated integrated data, the decryption function is not analyzed, and it is possible to prevent decryption without authority. it can.

  The best mode for carrying out the present invention will be described below with reference to the drawings as an embodiment. In addition, this invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the gist thereof.

  (Embodiment 1: Claims 1 and 9 will be mainly described)

  As Embodiment 1 of the present invention, a function for directly decrypting data based on the encrypted data and the function for decrypting the encrypted data is obtained. A processing device that generates integrated data not included will be described.

(Embodiment 1: Configuration)
FIG. 1 illustrates a functional block diagram of a processing apparatus according to Embodiment 1 of the present invention. The processing device 100 includes a data acquisition unit 101, an encryption function acquisition unit 102, a data encryption unit 103, a decryption function acquisition unit 104, and an integrated data generation unit 105.

  The “data acquisition unit” 101 acquires data. Data is not limited to a particular type or format. If the processing apparatus according to the present invention is an apparatus that mainly handles digital data, it may be data that can be stored as a file in a computer. For example, there are text data, programs (including compiled ones), still image data, audio data, moving image data, and the like. There are various modes of data acquisition. For example, a file name is designated, or data itself or data encoded into text data by BASE64 or the like is input to an input window. Further, data may be obtained by photographing with a camera or a microphone connected to the processing device. Further, data as a result of performing a simulation or the like in the processing apparatus may be obtained. In this sense, in this specification, “acquisition” includes the meaning of “generation”.

  The “encryption function acquisition unit” 102 acquires an encryption function that is a function for encrypting the data acquired by the data acquisition unit 101. In the present embodiment, the encryption function is not particularly limited. Any encryption function may be used. Note that although it is described as “encryption function”, the name “function” is used to mean the entire program for performing encryption. Although the name “procedure” may be used depending on the programming language, the term “procedure” is also included in the meaning of the term “function” in this specification.

  The “data encryption unit” 103 encrypts the data acquired by the data acquisition unit 101 using the encryption function acquired by the encryption function acquisition unit 102 to generate encrypted data. That is, it is a unit that applies an encryption function to data.

  The “decryption function acquisition unit” 104 acquires a decryption function for decrypting the encrypted data generated by the data encryption unit 103. That is, a decryption function that is paired with the encryption function acquired by the encryption function acquisition unit 102 is acquired. “Pairing” means that the data before applying the encryption function is obtained by applying the data encrypted by the encryption function to the decryption function. For example, when the encryption function applies XOR (exclusive OR) for each bit with a specific bit pattern, the decryption function is a function that applies XOR with the same bit pattern. If the encryption function is a function that performs encryption with a secret key of a public key cryptosystem, the decryption function is a function that performs decryption with a public key corresponding to the secret key.

  The “integrated data generation unit” 105 directly determines the decryption function based on the encrypted data generated by the data encryption unit 103 and the decryption function acquired by the decryption function acquisition unit 104. Integrated data that does not include information indicating

  The “decoding function” means a decoding function acquired by the decoding function acquisition unit 104. Further, “directly does not include information indicating the decoding function” means that the decoding function itself is not included, and the decoding function cannot be derived only by the integrated data. For example, the integrated data may not include a decryption function or information indicating it at all. Also, an identifier is assigned to the decryption function in advance, and the integrated data includes the identifier assigned to the decryption function so that the relationship between the decryption function and the identifier is kept secret. It may be.

  In the present embodiment, the integrated data generated by the integrated data generation unit 105 is configured to acquire the decryption function and the encrypted data by performing a predetermined operation.

  FIG. 2 schematically shows the relationship among the integrated data, the encrypted data, and the decryption function. For example, the integrated data 200 includes encrypted data 201 and a decryption function identifier 202 that is an identifier of the decryption function. By performing a predetermined operation, the encrypted data 201, the decryption function 203, , Has come to be obtained.

  “Predetermined operation” means a predetermined operation. For example, it means inputting integrated data into a predetermined program. The program reads integrated data, acquires encrypted data from the integrated data, and acquires a decryption function included in the program, for example. Alternatively, when the decryption function identifier is included in the integrated data as illustrated in FIG. 2, the decryption function identified by the decryption function identifier is acquired. For example, even if a secure communication path is secured by SSL or the like that can communicate with a communication network such as the Internet, the decryption function identifier is transmitted to the server, and the decryption function is acquired. Good.

(Embodiment 1: processing)
FIG. 3 exemplifies a process flowchart of the processing apparatus according to the present embodiment. In step S301, data is acquired by the data acquisition unit 101 or the like (data acquisition step). In step S302, the encryption function acquisition unit 102 or the like acquires the encryption function (encryption function acquisition step). In step S303, the data encryption unit 103 or the like generates encrypted data (data encryption step). In step S304, the decoding function acquisition unit 104 or the like acquires a decoding function (decoding function acquisition step). In step S305, the integrated data generation unit 105 or the like generates integrated data (integrated data generation step).

  As described above, the processing device according to the present embodiment uses a processing method including a data acquisition step, an encryption function acquisition step, a data encryption step, a decryption function acquisition step, and an integrated data generation step. It can also be seen as a device. However, an apparatus that uses the processing method according to the present embodiment is not limited to the processing apparatus according to the present embodiment.

  Further, the present invention is not limited to this embodiment, and each unit and each unit that is a component of the processing apparatus according to the present invention can be configured by either hardware, software, or both hardware and software (program). It is. For example, as an example for realizing these, when a computer is used, hardware composed of a CPU, a memory, a bus, an interface, a peripheral device, and the like, and software that can be executed on these hardware are listed. Can do.

(Embodiment 1: Main effects)
According to the present embodiment, since the integrated data does not include information directly indicating the decryption function, it is difficult to analyze (reverse engineer) decryption of the encrypted data included in the integrated data. , It is possible to prevent decryption without authority.

  (Embodiment 2: Claim 2 will be mainly described)

  As a second embodiment of the present invention, a description will be given of a processing apparatus in which the data size is the same before and after encryption as an encryption function.

(Embodiment 2: Configuration)
Embodiment 2 of the present invention is a processing apparatus according to Embodiment 1, in which the encryption function acquired by the encryption function acquisition unit 102 has the same size of the data before encryption and the data after encryption. It is.

  For example, a stream cipher that performs encryption byte by byte or bit by bit may be used. Also, if the data is a block unit size, an encryption function that performs encryption in block units such as DES (Data Encryption Standard) may be used.

  An example of the stream cipher is one that uses a reversible instruction of the CPU. FIG. 4 summarizes examples of reversible instructions for each instruction size (number of bytes). A “reversible instruction” refers to an instruction in which there is an instruction to restore the original (a pair of instructions) even if data is manipulated by the instruction. For example, an instruction that adds 1 to a register value is a reversible instruction because there is an instruction that subtracts 1 from a register value.

  Therefore, the encryption function acquisition unit 102 randomly selects the instruction illustrated in FIG. 4, and if the instruction has Immediate, generates the value, and generates the encryption function by arranging the instructions. It may be like this. Then, the decryption function acquisition unit 104 arranges the instructions constituting the encryption function in reverse and replaces them with a pair of instructions.

  FIG. 5 illustrates the relationship between the encryption function and the decryption function generated in this way. It is exemplified that the decryption function is generated by arranging the instructions in the reverse order of the encryption functions and replacing the instructions in pairs.

  The integrated data does not include information indicating the decryption function directly, but for example, the hash value of the encryption function may be held as a decryption function identifier. When a predetermined operation is performed, the encryption function is searched based on the decryption function identifier that is a hash value to generate a decryption function. Of course, if the encryption function is generated completely at random, the search process becomes difficult. Therefore, some encryption function patterns may be determined to reduce the amount of search calculation.

(Embodiment 2: Main effects)
In the present embodiment, in addition to the effects of the first embodiment, the size of the data and the encrypted data is the same. Therefore, when generating the integrated data, the area where the data is held is set as the area where the encrypted data is held. It can be used and the working space of the processing apparatus can be prevented from increasing. For example, as illustrated in FIG. 6, first, the data 602 can be included in the integrated data 601, and then the encrypted data 603 can be included in the integrated data by encrypting the data. .

  (Third embodiment: Claim 3 will be mainly described.)

  As a third embodiment of the present invention, a processing apparatus that encrypts a decryption function and includes it in integrated data will be described.

(Embodiment 3: Configuration)
FIG. 7 illustrates a functional block diagram of the processing apparatus according to the third embodiment of the present invention. The processing device 700 includes a data acquisition unit 101, an encryption function acquisition unit 102, a data encryption unit 103, a decryption function acquisition unit 104, and an integrated data generation unit 105. The integrated data generation unit 105 Includes a decryption function encryption unit 701 and an encryption function use generation unit 702. Therefore, the processing apparatus 700 according to the present embodiment is configured such that the integrated data generation unit 105 of the processing apparatus according to the first or second embodiment includes the decryption function encryption unit 701 and the encryption function use generation unit 702. It has become.

  The “decryption function encryption unit” 701 encrypts the decryption function. For example, encryption is performed using the encryption method described with reference to FIGS.

  The “encryption function utilization generating unit” 702 generates the integrated data based on the encryption / decryption function that is the decryption function encrypted by the decryption function encryption unit 701. Since the encryption / decryption function does not directly include information indicating the decryption function, the encryption / decryption function is included in the integrated data.

  FIG. 8 schematically illustrates the structure of integrated data generated by the processing apparatus according to this embodiment. The integrated data 801 includes an encryption / decryption function 802 and encrypted data 803. When performing a predetermined operation, an encryption / decryption function is extracted from the integrated data 801, a function for decrypting the encryption / decryption function is acquired, and a process for obtaining the decryption function is performed. For example, if the pattern of the encryption function is limited to some extent, and if the pattern of the decryption function is also limited to some extent, the pattern of the encryption / decryption function is also limited to some extent, so than the encryption / decryption function, It is possible to obtain a decoding function by obtaining a function for performing decoding.

  In addition, as shown in FIG. 9, information 901 for decrypting the encryption function 902 may be included in the integrated data 901. The information 901 may be, for example, a decryption key for decrypting the encryption / decryption function or a program for decrypting the encryption / decryption function. Further, such a decryption key or program may be encrypted by a predetermined method.

(Embodiment 3: Main effects)
According to the present embodiment, in addition to the effects of the first or second embodiment, since the encryption / decryption function can be included in the integrated data, it is possible to simplify the process of decrypting the encrypted data in the predetermined process.

  (Embodiment 4: Claim 4 will be mainly described)

  As a fourth embodiment of the present invention, a processing device in which the decryption function and the encryption / decryption function have the same size will be described.

(Embodiment 4: Configuration)
The processing device according to the fourth embodiment of the present invention is the same as the processing device according to the third embodiment, except that the decryption function and the encryption / decryption function have the same size. As described in the second embodiment, when the stream cipher is used, the encryption method described with reference to FIGS. 4 and 5 is used, or the size of the decryption function is the size of the block unit, the block unit is used. For example, an encryption function that performs encryption is used.

(Embodiment 4: Main effects)
In the present embodiment, in addition to the effects of the third embodiment, the sizes of the decryption function and the encryption / decryption function are equal. Therefore, when a predetermined operation is performed, the area of the decryption function Since it can be used as an area, the work space can be prevented from increasing.

  (Embodiment 5: Claim 5 will be mainly described)

  As a fifth embodiment of the present invention, a processing apparatus in which integrated data is a program will be described.

(Embodiment 5: Configuration)
The processing device according to the fifth embodiment of the present invention is a processing device according to any one of the first to fourth embodiments, in which the integrated data is a program. The program is to be executed.

  That is, the integrated data can be executed, the decryption function and the encrypted data are acquired by executing the integrated data, and the data can be obtained by applying the decryption function to the encrypted data. Become.

  If the processing apparatus according to the present embodiment is based on the first or second embodiment, the integrated data as a program obtains a decryption function from a server connected to a communication network such as the Internet, for example. It may be like this.

  In addition, when the processing apparatus according to the present embodiment is based on the third or fourth embodiment, the integrated data that is a program acquires and decrypts an encryption / decryption function included in itself. We will get the decryption function and apply it to the encrypted data.

  FIG. 10 illustrates a flowchart of a process for obtaining data from the integrated data generated by the processing apparatus according to the present embodiment. In step S1001, a decryption function is obtained using a function for decrypting from the encryption / decryption function. In step S1002, data is obtained from the encrypted data using a decryption function.

(Embodiment 5: Main effects)
According to the present embodiment, in addition to the main effects of any of the first to fourth embodiments, data can be obtained directly from the integrated data.

  (Embodiment 6: Claim 6 will be mainly described)

  As a sixth embodiment of the present invention, a processing apparatus in which a decryption function and data obtained by a predetermined operation are held only in the main memory of a computer will be described.

(Embodiment 6: Configuration)
A processing device according to a sixth embodiment of the present invention provides a data obtained by applying the decryption function obtained by the predetermined operation to the processing device according to the fifth embodiment and the encrypted data to the decryption function. Is held only in the main memory of the computer. The “predetermined operation” is to execute integrated data. The “decoding function” means the same decoding function acquired by the decoding function acquisition unit 104. The “encrypted data” is encrypted data that is the basis when the integrated data is generated. The “computer” means a computer on which integrated data as a program is executed.

  Therefore, the integrated data, which is a program, does not use a file or the like as a work area for obtaining data, but uses only the memory in the main memory.

  Further, the decryption function may perform processing such that the memory of the process that executes the integrated data that is a program is not read. In the normal computer operating system, the memory of other processes cannot be read, but the memory of other processes can be read by using special system calls such as for realizing the debugger. Can do. Therefore, a special device driver is incorporated into the operating system, and a system call for reading the memory of another process is hooked so that the memory of the specific process cannot be read. Then, the decryption function sets the special device driver (for example, using an ioctl system call), and sets its own process as the specific process. Thereby, even if a debugger etc. are used, a decryption function and data can be prevented from being acquired by others.

(Embodiment 6: Main effects)
According to the present embodiment, in addition to the main effects of the fifth embodiment, since the decoding function and data are held only in the main memory, it becomes difficult to obtain the decoding function and data.

  (Embodiment 7: Claim 7 will be mainly described)

  As a seventh embodiment of the present invention, a processing apparatus is described in which execution of the program is started by acquiring the program as data and executing the integrated data.

(Embodiment 7: Configuration)
In the processing device according to the seventh embodiment of the present invention, the data acquired by the data acquisition unit 101 in the processing device according to the fifth or sixth embodiment is a program. The integrated data is a program for causing a computer to execute an acquisition step, a data acquisition step, and an execution step. Here, the “integrated data” is integrated data generated by the integrated data generation unit 105. The “acquiring step” is a step of acquiring the decryption function and the encrypted data. The “decryption function” and “encrypted data” are a decryption function and encrypted data that are the basis for generating the integrated data. The “data acquisition step” is a step of acquiring data by applying the encrypted data to the decryption function. The “execution step” is a step of executing the data acquired in the data acquisition step.

  In the acquisition step, for example, a decryption function is acquired and held in a memory or the like, and the position or size of encrypted data included in the integrated data is specified.

  In the data acquisition step, the position and size of the encrypted data are given to the decryption function acquired in the acquisition step, and the encrypted data is decrypted to obtain data. The obtained data is held in a memory or the like.

  In the execution step, if the data obtained in the data acquisition step is in the memory, the program counter is set to the entry point address. If the data is in a file, a system call (for example, execute) for executing the file is executed.

  In the present embodiment, when data that is a program is acquired by the data acquisition unit, operations such as clearing the symbol table or clearing the import table of the shared library may be performed. For example, if the symbol table is cleared, even if the data is acquired by another person, even if the program such as disassembly is analyzed, the function name or the like is not displayed, so that the analysis becomes difficult. Also, by clearing the import table, it is difficult to find out what kind of library the program uses, and it is difficult to know how the program is written.

  Further, when decrypting the encryption / decryption function, a technique called a running line using a trap handler may be used. The running line means that every time the CPU executes one instruction, it interrupts the CPU to call a trap handler and repeatedly determines the address of the instruction to be executed next (see FIG. 13). This makes it possible to insert a meaningless sequence of instructions between the instructions, which makes it difficult to analyze the program. In the running line, since the program is analyzed when the trap handler is analyzed, it is preferable to encrypt the trap handler in advance and decrypt it at the time of execution.

  FIG. 11 schematically illustrates the structure of integrated data generated by the processing apparatus according to the present embodiment. The integrated data 1101 includes a trap handler decryption function, so that the encrypted trap handler 1103 can be decrypted. Further, a function 1104 for decrypting the encryption / decryption function is also included, and thereby the encryption / decryption function 1105 is decrypted. At this time, a running line may be used. Note that the running line may be performed throughout the execution of the function 1104 for decrypting the encryption / decryption function. However, in the running line, the trap handler is called for each instruction, and the processing speed decreases. Therefore, the running line may be executed by a part of the function 1104 for decrypting the encryption / decryption function. For example, when the decryption key for decrypting the encryption / decryption function or the decryption function illustrated in FIG. 5 is encrypted, the running line is used only when decrypting the encrypted decryption key. May be used.

  FIG. 12 is a flowchart for explaining the operation of integrated data that is a program. In step S1201, the encrypted trap handler is decrypted. For example, decoding is performed by calculating XOR for each bit according to a specific bit pattern. In step S1202, a trap handler is set. “Set” is to call a trap handler when a predetermined condition is satisfied. In the running line, the predetermined condition is that one instruction is executed. In step S1203, a decryption function is obtained from the decryption function using the decryption function. In step S1204, the trap handler is reset. In step S1205, the encrypted data is decrypted using the decryption function. In step S1206, the data is executed.

  FIG. 14 illustrates a change in the integrated data illustrated in FIG. 11 that occurs by performing a predetermined operation. First, in step S1201, the encrypted trap handler is decrypted, and integrated data exemplified in FIG. 14 is obtained. Next, in step S1203, the encryption / decryption function is decrypted, and integrated data illustrated in the center of FIG. 14 is obtained. In step S1205, the encrypted data is decrypted, and integrated data illustrated at the bottom of FIG. 14 is obtained.

(Embodiment 7: Main effects)
According to the present embodiment, in addition to the main effects of the fifth or sixth embodiment, by encrypting the program and including it in the integrated data, the program can be safely distributed in a state where analysis is difficult.

  (Embodiment 8: Claim 8 will be mainly described)

  As an eighth embodiment of the present invention, a description will be given of a processing apparatus having a function for a decoding function to confirm the presence of a debugger.

(Embodiment 8: Configuration)
The processing apparatus according to the eighth embodiment of the present invention is such that the decoding function in the processing apparatus according to the sixth or seventh embodiment has a function of confirming whether or not the debugger exists in the computer on which the integrated data is executed. It is a thing. It has the purpose of preventing execution of integrated data from being analyzed due to the presence of a debugger in the computer.

  As a method of detecting the debugger, there is a method of detecting whether or not a file having a debugger command name exists in a directory or folder in which the debugger is normally installed. Depending on the operating system, debugger information is recorded in a location called a registry, and the presence or absence of the recording may be checked. In addition, if there is a debugger called SoftICE, the difference in the address of the event handler becomes a predetermined value, or there is a special device, which may be detected. Various detection methods of SoftICE are described in Chapter 7 of Non-Patent Document 1.

  If it is detected that a debugger exists, the encrypted data can be prevented from being decrypted.

(Embodiment 8: Main effects)
In the present embodiment, in addition to the main effects of the sixth or seventh embodiment, when a debugger or the like is present, it is possible to prevent the decryption of the encrypted data, thereby making it difficult to analyze. be able to.

  Since the integrated data generated by the processing apparatus and the processing method according to the present invention does not include the decryption function directly, the decryption function is not analyzed and the decryption is performed without title. This is useful because it can be prevented.

Functional block diagram of the processing apparatus according to the first embodiment of the present invention. Example of relationship between integrated data, encrypted data, and decryption function Process flow of processing apparatus according to Embodiment 1 of the present invention An example of reversible instructions The figure which shows the relationship between the encryption function and the decryption function which consist of the reversible instruction Example diagram for explaining the effect of the invention Functional block diagram of a processing apparatus according to Embodiment 3 of the present invention Example of integrated data structure Example of structure of integrated data including information for decrypting encryption function Flow chart of processing of integrated data generated by the processing apparatus according to the fifth embodiment of the present invention. Structure of integrated data generated by processing apparatus according to embodiment 7 of the present invention Flow chart explaining the operation of integrated data that is a program Illustration for explaining the running line Diagram for explaining changes in integrated data Example of conventional encryption format

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Processing apparatus 101 Data acquisition part 102 Encryption function acquisition part 103 Data encryption part 104 Decryption function acquisition part 105 Integrated data generation part

Claims (4)

A data acquisition unit for acquiring data;
An encryption function acquisition unit that acquires an encryption function that is a function for encrypting data acquired by the data acquisition unit;
A data encryption unit that encrypts the data acquired by the data acquisition unit and generates encrypted data by the encryption function acquired by the encryption function acquisition unit;
A decryption function obtaining unit for obtaining a decryption function for decrypting the encrypted data generated by the data encryption unit;
A decryption function identifier that is an identifier of the decryption function based on the encrypted data generated by the data encryption unit and the decryption function acquired by the decryption function acquisition unit , and is encrypted An integrated data generation unit that generates integrated data that does not include the decryption function ;
Have
The integrated data generated by the integrated data generation unit can acquire the decryption function and the encrypted data by an execution operation in a computer, and the acquired decryption function and the encrypted data A processing apparatus which is a program configured to hold data obtained by applying to a decryption function only in the main memory of the computer .   The processing apparatus according to claim 1, wherein the data acquired by the data acquisition unit is a program.   The processing apparatus according to claim 1, wherein the decryption function has a function of confirming whether a debugger exists in a computer in which integrated data is executed. A data acquisition step for acquiring data;
An encryption function obtaining step for obtaining an encryption function that is a function for encrypting the data obtained in the data obtaining step;
A data encryption step of generating encrypted data by encrypting the data acquired in the data acquisition step by the encryption function acquired in the encryption function acquisition step;
A decryption function obtaining step for obtaining a decryption function for decrypting the encrypted data generated by the data encryption step;
A decryption function identifier that is an identifier of the decryption function based on the encrypted data generated by the data encryption step and the decryption function acquired by the decryption function acquisition step , and is encrypted An integrated data generation step for generating integrated data not including a decryption function ;
A computer processing method including:
The integrated data generated in the integrated data generating step is
The decryption function and the encrypted data can be acquired by an execution operation in the computer, and the data obtained by applying the acquired decryption function and the encrypted data to the decryption function is stored in the computer. A processing method for a computer, which is a program configured to be held only in the main memory .

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