JP2018180408A - Encryption processing method, encryption processing system, encryption device, decryption device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an encryption technology capable of adding an attribute ID or an attribute value acquisition method without modifying a system.SOLUTION: An encryption device 300 generates an encrypted text from a plaintext, a decryption condition and encryption option information by using a public parameter. A decryption device 500 acquires an attribute ID used under the decryption condition used for generating the encrypted text and environmental information as its value by using the encryption option information used for generating the encrypted text received from the encryption device 300, and transmits them to a decryption key generation device 400. The decryption key generation device 400 generates a decryption key from the environmental information received from the decryption device 500 and a master key, and transmits the decryption key to the decryption device 500. The decryption device 500 decrypts the encrypted text by using the decryption key received from the decryption key generation device 400.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an encryption technique that can be used for access control that prevents unauthorized use of concealed data.

  In functional-type cryptography, which is an advanced technology of public key cryptography, a condition (hereinafter referred to as a decryption condition) regarding a person or group that can be decrypted at the time of encryption is a logic using a general logical expression (AND operator, OR operator, etc. It has the feature that it can be designated by the formula) (Non-Patent Document 1). For example, the value of attribute ID "gid" representing a group ID (hereinafter also referred to as attribute value) is either "GID 01" or "GID 02", and the value of attribute ID "date" representing a date is "20170302". A logical expression indicating that access is permitted in a certain case is {(gid = GID01) OR (gid = GID02)} AND (date = 20170302). This logical expression can access encrypted data only when a person whose group ID "gid" is either "GID01" or "GID02" has a date "date" of "20170302". Can be decoded).

  When using functional encryption, the data to be concealed is managed in the cloud as encrypted data with the decryption condition represented by the above logical expression, and the user sets the decryption condition that matches his / her attribute value It is possible to realize a cryptographic processing system provided with access control that can decrypt only the encrypted data.

Katsuyuki Takashima, Takuaki Okamoto, "The Latest Technology for Controlling Access Authority" Functional Cryptography ", Nikkei Electronics (1087) 2012-07-23, Nikkei BP, pp. 87-95, 2012.

  In a cryptographic processing system using functional encryption, at the time of system design, an attribute ID used to control access authority is specified. Therefore, when adding and using a new attribute ID which has not been designated at the time of system design, it is necessary to regenerate the public parameter and the master key (hereinafter referred to as a system parameter).

  In addition, the method for acquiring attribute values is also specified at the time of system design. Therefore, when adding a new acquisition method, it is necessary to modify the system.

  That is, when adding a new attribute ID or a new attribute value acquisition method, it was necessary to modify the system.

  Therefore, it is an object of the present invention to provide an encryption technique that enables addition of an attribute ID and addition of an attribute value acquisition method without modifying the system.

  One aspect of the present invention is that M, N is an integer of 1 or more, standard attribute ID is an attribute ID whose application is already defined, extended attribute ID is an attribute ID whose application is undefined, attribute ID list is M pieces An encryption processing method in which an encryption processing system including a system parameter generation device, an encryption device, a decryption key generation device, and a decryption device as a list including a standard attribute ID and N extended attribute IDs performs encryption and decryption. The encryption device records the public parameter generated by the system parameter generation device from the attribute ID list, and the decryption key generation device generates a master key generated by the system parameter generation device from the attribute ID list Is a logical combination of primitive logical expressions using standard attribute IDs or extended attribute IDs included in the attribute ID list. Formula, encryption option information is information specified by using the attribute ID included in the attribute ID list, and the encryption device uses the public parameter to calculate the plaintext, the decryption condition, and the encryption option information The ciphertext generation step of generating a ciphertext; and the decryption used for generation of the ciphertext using the encryption option information used for generation of the ciphertext received by the decryption apparatus from the encryption apparatus An environment information acquisition step of acquiring environment information which is an attribute ID and its value used in the condition, and the decryption key generation device generates a decryption key from the environment information received from the decryption device and the master key And a decryption step of decrypting the ciphertext by using the decryption key received from the decryption key generation device.

  According to the present invention, it is possible to add an attribute ID and an attribute value acquisition method without modifying the system.

FIG. 1 is a block diagram showing an example of the configuration of a cryptographic processing system 100. FIG. 2 is a block diagram showing an example of the configuration of a system parameter generation device 200. FIG. 2 is a block diagram showing an example of the configuration of an encryption apparatus 300. FIG. 7 is a block diagram showing an example of the configuration of a decryption key generation device 400. FIG. 16 is a block diagram showing an example of the configuration of a decoding device 500. The sequence diagram which shows an example of a setup process. The sequence diagram which shows an example of encryption processing. The sequence diagram which shows an example of a decoding process. The figure which shows the mode of handling of encryption option information (definition of the use of extended attribute ID). The figure which shows the mode of handling of encryption option information (designation of acquisition method of attribute value of attribute ID).

Hereinafter, embodiments of the present invention will be described in detail. Note that components having the same function will be assigned the same reference numerals and redundant description will be omitted.
First Embodiment

[System configuration]
The cryptographic processing system 100 is a system that provides access control for encrypted data, which is data obtained by encrypting plaintext, using functional encryption. The system parameter generation device 200 generates a public parameter and a master key, which are information necessary for encryption / decryption. The encryption apparatus 300 generates a ciphertext from the plaintext, the decryption condition, and the encryption option information using the public parameter. The decryption key generation device 400 generates a decryption key using the attribute ID used in the decryption condition and the environment information and the master key that are the value thereof. The environment information is information that the decryption device 500 acquires and transmits to the decryption key generation device 400, and information on the decryption device 500 and the user who uses the decryption device 500 (for example, the group ID “gid” and its value) , General information (eg, date "date" and its value). The decryption apparatus 500 decrypts the ciphertext using the decryption key.

  The cryptographic processing system 100 will be described with reference to FIG. FIG. 1 is a block diagram showing an example of the configuration of the cryptographic processing system 100. As shown in FIG. The cryptographic processing system 100 includes a system parameter generation device 200, an encryption device 300, a decryption key generation device 400, and a decryption device 500. The system parameter generation device 200, the encryption device 300, the decryption key generation device 400, and the decryption device 500 are connected to a network 800 such as the Internet and can communicate with each other.

  Next, each of the system parameter generation device 200, the encryption device 300, the decryption key generation device 400, and the decryption device 500 will be described with reference to FIGS. FIG. 2 is a block diagram showing an example of the configuration of the system parameter generation device 200. As shown in FIG. The system parameter generation device 200 includes a system parameter generation unit 210, a transmission / reception unit 280, and a recording unit 290. The transmission and reception unit 280 is a component for appropriately transmitting and receiving information that the system parameter generation device 200 needs to exchange with other devices. The recording unit 290 is a component that appropriately records information necessary for the process of the system parameter generation device 200. For example, the attribute ID used for system parameter generation is recorded.

  FIG. 3 is a block diagram showing an example of the configuration of the encryption device 300. As shown in FIG. The encryption device 300 includes a ciphertext generation unit 310, a transmission / reception unit 380, and a recording unit 390. The transmission and reception unit 380 is a component for appropriately transmitting and receiving information that the encryption device 300 needs to exchange with other devices. The recording unit 390 is a component that appropriately records information necessary for the process of the encryption device 300. For example, the public parameter and attribute ID are recorded. The attribute ID is used to describe decryption conditions and encryption option information.

  FIG. 4 is a block diagram showing an example of the configuration of the decryption key generation device 400. As shown in FIG. The decryption key generation device 400 includes a decryption key generation unit 410, a transmission / reception unit 480, and a recording unit 490. The transmitting and receiving unit 480 is a component for appropriately transmitting and receiving information that the decryption key generation device 400 needs to exchange with another device. The recording unit 490 is a component that appropriately records information necessary for the processing of the decryption key generation device 400. For example, the master key is recorded.

  FIG. 5 is a block diagram showing an example of the configuration of decoding apparatus 500. The decryption apparatus 500 includes an environment information acquisition unit 510, a decryption unit 520, a transmission / reception unit 580, and a recording unit 590. The transmitting and receiving unit 580 is a component for appropriately transmitting and receiving information that the decoding device 500 needs to exchange with other devices. The recording unit 590 is a component that appropriately records information necessary for the process of the decoding device 500. For example, the ciphertext is recorded.

[Setup process]
Hereinafter, with reference to FIG. 6, a setup process for generating a public parameter and a master key which are system parameters will be described.

  At the time of setup processing, an attribute ID used to describe decryption conditions of encrypted data is designated. The attribute ID includes a standard attribute ID whose use is already defined and an extended attribute ID whose use is undefined. Here, that the application of the attribute ID is defined means that a possible value of the attribute ID and a method of acquiring the value are defined.

  Examples of the standard attribute ID include an attribute ID "gid" representing a group ID and an attribute ID "date" representing a date. The extended attribute ID has an ID name different from the standard attribute ID. For example, the extended attribute ID is "ext_info1", "ext_info2" or the like. The use of the extended attribute ID is defined using encryption option information which is additional information on the decryption condition.

  The encryption option information can include, in addition to the definition of the use of the extended attribute ID, a description on the specification of the method of acquiring the attribute value of the attribute ID. Details will be described later.

  Hereinafter, it is assumed that the number of standard attribute IDs used for generation of system parameters is M, and the number of extended attribute IDs is N (M and N are integers of 1 or more). A list consisting of M standard attribute IDs and N extended attribute IDs is called an attribute ID list.

  The system parameter generation unit 210 of the system parameter generation device 200 generates the public parameter pk and the master key mk from the attribute ID list using the functional encryption (S210). At that time, a security parameter that represents a measure of cryptographic security may be specified.

  In addition, as long as it is a functional encryption algorithm, what kind of thing may be used for the production | generation of the open parameter pk and the master key mk.

  The transmission / reception unit 280 of the system parameter generation device 200 transmits the public parameter pk generated in S210 to the encryption device 300 (S280-1). The encryption device 300 records the received public parameter pk in the recording unit 390. The public parameter pk is information required for encryption.

  The transmission / reception unit 280 of the system parameter generation device 200 transmits the master key mk generated in S210 to the decryption key generation device 400 (S280-2). The decryption key generation device 400 records the received master key mk in the recording unit 490. The master key mk is information necessary for decryption.

  The order of S280-1 and S280-2 is not limited to the above order, and the order of S280-2 and S280-1 may be or may be simultaneous.

[Encryption processing]
Hereinafter, the encryption processing for generating a ciphertext from plaintext which is data to be concealed will be described with reference to FIG.

  In the encryption process, decryption conditions and encryption option information are specified. The encryption option information is designated as necessary.

  The decoding condition is a primitive logical expression using attribute ID (standard attribute ID or extended attribute ID included in attribute ID list) as logical operator (for example, AND operator, OR operator, NOT operator, threshold operation) It is expressed as a logical expression connected by a child etc.). The above-mentioned logical expression {(gid = GID01) OR (gid = GID02)} AND (date = 20170302) is an example of a decoding condition, and primitive logical expressions (gid = GID01), (gid = GID02), ( It is a logical expression in which date = 20170302) is combined with the OR operator and the AND operator.

  The encryption option information describes the definition of the purpose of the extended attribute ID and the specification of the method of acquiring the attribute value of the attribute ID, and is information specified using the attribute ID included in the attribute ID list.

  First, an example of definition of usage of extended attribute ID will be described (see FIG. 9). For example, when describing “ext_info1ggid” using the extended attribute ID “ext_info1”, the attribute ID “ext_info1” having a new ID name for holding the value of the standard attribute ID “gid” representing the group ID is It will be defined. As a result, the attribute ID "ext_info1" obtained by renaming the name of the standard attribute ID "gid" can be used to specify the decryption condition.

  Also, the extended attribute ID can be used to define a new attribute ID different from the M standard attribute IDs instead of simply defining the usage of the extended attribute ID as a renaming of the existing attribute ID. Hereinafter, description will be made using an example. In the application “app_B” installed in the decryption apparatus 500, the attribute ID “uid” can be handled. That is, in the application “app_B”, it is assumed that the possible values of the attribute ID “uid” and the method of acquiring the values are defined. In this example, it is assumed that there is no application installed in the decryption apparatus 500 that can handle the attribute ID “uid” other than the application “app_B”. If there are a plurality of applications that can handle the attribute ID “uid”, the application package name and class name described later can be specified by a method of specifying in the encryption option information. At this time, if “ext_info1 ← uid” is described using the extended attribute ID “ext_info1”, the undefined extended attribute ID “ext_info1” holds the value of the attribute ID “uid” of the application “app_B”. It is defined as the attribute ID of. After that, it becomes possible to describe the condition related to the attribute ID “uid” representing the user ID in the specification of the decryption condition.

  For example, when an application package name such as “app_A.app_A_class.param00”, a class name, and a parameter name are used to describe “ext_info11app_A.app_A_class.param00”, the application package installed in the decryption apparatus 500 ” Attribute ID "ext_info1" for holding the value of parameter "param00" of class "app_A_class" of app_A "is defined. As a result, the attribute ID "ext_info1" for holding the value of the parameter "param00" of the class "app_A_class" included in the application package "app_A" can be used to specify the decryption condition.

  Further, for example, if “ext_info1 ← app_A.app_A_class” is described using a combination of application package name and class name as “app_A.app_A_class”, the class of application package “app_A” installed in the decryption apparatus 500 The attribute ID "ext_info1" for holding the value of a certain parameter of "app_A_class" is defined. When there are a plurality of parameters used in the class "app_A_class", the application decides which value of the parameter is to be returned as the value of the extended attribute ID "ext_info1". Alternatively, a value to be acquired may be designated in the encryption option information. As a result, the attribute ID "ext_info1" for holding the value of the parameter of the class "app_A_class" included in the package "app_A" can be used to specify the decryption condition.

  Next, an example of designation of a method of acquiring the attribute value of the attribute ID will be described (see FIG. 10). For example, if “ext_info1 ← http: //xxx.com” is described, acquiring the attribute value of the attribute ID “ext_info1” from the Web server outside the system specified by the URL “http://xxx.com” It will be specified. As a result, the value (http response) of the output from “http://xxx.com” is held in the attribute ID “ext_info1”.

  Also, for example, if “date date http://xxx.com” is described using the standard attribute ID “date”, the URL “instead of acquiring the attribute value of the attribute ID“ date ”according to the system default method It will be specified to acquire from a web server outside the system specified by http://xxx.com.

  The ciphertext generation unit 310 of the encryption device 300 generates a ciphertext D from the plaintext M, the decryption condition c, and the encryption option information op using the public parameter pk (S310). The plaintext M is information that the user of the encryption device 300 wants to share with the user of the decryption device 500. Further, the decryption condition c and the encryption option information op are designated by the user of the encryption device 300, and the access condition to the plaintext M is designated using these information.

  The method of generating the ciphertext D will be described. For example, the encrypted data C is generated from the plaintext M and the decryption condition c using the public parameter pk, and the ciphertext D is generated as a set of the encrypted data C and the encryption option information op. Alternatively, encrypted data C may be generated from plaintext M and decryption condition c using public parameter pk, and ciphertext D may be generated as a combination of encrypted data C, decryption condition c and encryption option information op. .

  If the ciphertext does not have a format in which the decryption device 500 can specify the attribute ID used for describing the decryption condition and the encryption option information before receiving the decryption key sk in S480 described later, all the attributes Environment information can be acquired by acquiring the value of the ID. On the other hand, if the decryption text is in a format that allows the decryption device 500 to specify the attribute ID used for describing the decryption condition and the encryption option information before receiving the decryption key sk in S480, Environment information can be efficiently acquired because the value of the attribute ID used in the description may be acquired.

  The transmission / reception unit 380 of the encryption device 300 transmits the ciphertext D generated in S310 to the decryption device 500 (S380). The decryption device 500 records the received ciphertext D in the recording unit 590.

[Decryption processing]
The decryption processing for decrypting the ciphertext will be described below with reference to FIG.

  The environment information acquisition unit 510 of the decryption apparatus 500 uses the encryption option information op used to generate the ciphertext D, and uses the attribute ID used in the decryption condition c used to generate the ciphertext D and the value thereof. Certain environmental information α is acquired (S510).

  When the ciphertext D is a set of the encrypted data C and the encryption option information op, the environment information acquisition unit 510 extracts the encryption option information op from the ciphertext D, and uses the encryption option information op to perform all the operations. For the attribute ID of, the value is acquired, and the environment information α is acquired. When the ciphertext D is a combination of the encrypted data C, the decryption condition c, and the encryption option information op, the environment information acquisition unit 510 extracts the decryption condition c and the encryption option information op from the ciphertext D, For the attribute ID used in the decryption condition c, the value is acquired, and the environment information α is acquired.

  The transmission / reception unit 580 of the decryption apparatus 500 transmits the environment information α acquired in S510 to the decryption key generation apparatus 400 (S580). The decryption key generation device 400 records the received environment information α in the recording unit 490.

  The decryption key generation unit 410 of the decryption key generation device 400 generates the decryption key sk from the environment information α received in S580 and the master key mk recorded in the recording unit 490 (S410).

  The transmission / reception unit 480 of the decryption key generation device 400 transmits the decryption key sk generated in S410 to the decryption device 500 (S480). The decryption apparatus 500 records the received decryption key sk in the recording unit 590.

  The decryption unit 520 of the decryption apparatus 500 decrypts the ciphertext D recorded in the recording unit 590 using the decryption key sk received in S480 (S520). When the environment information α satisfies the decryption condition c, the decryption result is a correct plaintext, whereas when the environment information α does not satisfy the decryption condition c, the decryption result is a random value that does not make sense.

  In the above description, the transmission / reception unit 580 always transmits the environment information α to the decryption key generation device 400. However, when the decryption condition c can be extracted from the ciphertext D, whether the environment information α satisfies the decryption condition c before the transmitting / receiving unit 580 transmits the environment information α to the decryption key generation device 400 It is possible to judge whether or not to transmit, when satisfying, but to stop the processing when not satisfying. In this way, the decryption unit 520 always decrypts the plaintext M correctly from the ciphertext D.

[Encryption option information]
(Definition of usage of extended attribute ID)
When describing the definition of the use of the extended attribute ID in the encryption option information, the extended attribute ID which has been undefined at the time of setup processing is used.

  The handling of the encryption option information will be described below with reference to FIG. First, at the time of encryption processing, for example, “ext_info1 ← gid” is specified as the encryption option information op. In addition, as the decryption condition c, for example, {(ext_info1 = GID01) OR (ext_info1 = GID02)} AND (date = 20170302) is specified. The ciphertext generation unit 310 of the encryption device 300 generates a ciphertext D from the encryption option information op and the decryption condition c.

  Next, at the time of decryption processing, the environment information acquisition unit 510 of the decryption apparatus 500 acquires the value of the attribute ID “gid” based on the encryption option information op “ext_info 1 g gid” used for generating the ciphertext D. Do. Since the attribute ID "gid" is a standard attribute ID, for example, a method defined at the system design stage is used as a method of acquiring the attribute value. If the standard attribute ID is not used, an acquisition method when defining the application of the extended attribute ID is used. When the value acquired by the predetermined method is "GID02" as described above, "ext_info1 = GID02" is obtained. Similarly, regarding the attribute ID "date", when the acquired value is "20170302", "date = 20170302" is obtained. The transmission / reception unit 580 of the decryption apparatus 500 transmits “ext_info1 = GID02” and “date = 20170302” to the decryption key generation apparatus 400 as the environment information α.

  The decryption key generation unit 410 of the decryption key generation device 400 generates the decryption key sk from the environment information α′′ext_info1 = GID02 ′ ′ and “date = 20170302” and the master key mk. The transmission / reception unit 480 of the decryption key generation device 400 transmits the decryption key sk to the decryption device 500.

  The decryption unit 520 of the decryption apparatus 500 decrypts the ciphertext D using the decryption key sk. In this case, the decryption condition c is {(ext_info1 = GID01) OR (ext_info1 = GID02)} AND (date = 20170302), and the decryption key sk is generated from the environment information α "ext_info1 = GID02", "date = 20170302" The plaintext is correctly decrypted. On the other hand, for example, when the decryption key sk is generated with the environment information α as “ext_info1 = GID03”, “date = 20170302”, the decryption unit 520 does not make sense because the decryption condition c is not satisfied. It will generate a value.

  As described above, by defining the purpose of the extended attribute ID that was undefined at the setup processing time in the encryption option information, it becomes possible to specify the decryption condition using the extended attribute ID, so system parameters There is no need to regenerate the

  In the previous example, encryption option information op "ext_info1 1 gid" was specified using one extended attribute ID "ext_info1", but the number allowed by the system, that is, the number of extended attribute IDs specified during setup processing The definition of usage of multiple extended attribute IDs can also be described in the encryption option information.

(Specification of acquisition method of attribute value of attribute ID)
When specifying the acquisition method of the attribute value of the attribute ID in the encryption option information, the standard attribute ID or the extended attribute ID is used.

  Hereinafter, the handling of the encryption option information will be described with reference to FIG. First, at the time of encryption processing, for example, “ext_info1 ← gid” and “ext_info1 ← http: //xxx.com” are designated as the encryption option information op. In addition, as the decryption condition c, for example, {(ext_info1 = GID01) OR (ext_info1 = GID02)} AND (date = 20170302) is specified. The ciphertext generation unit 310 of the encryption device 300 generates a ciphertext D from the encryption option information op and the decryption condition c.

  Next, at the time of decryption processing, the environment information acquisition unit 510 of the decryption apparatus 500 sets the value of the attribute ID “gid” based on “ext_info1 ← gid” of the encryption option information op used to generate the ciphertext D. get. Here, since “ext_info1 ← http: //xxx.com” is specified in the encryption option information op, instead of acquiring the value of the attribute ID “gid” by the default method, the external web server “http” is obtained. Get from: xxx.com If this value is "GID01", then "ext_info1 = GID01". Similarly, regarding the attribute ID "date", when the acquired value is "20170302", "date = 20170302" is obtained. The transmission / reception unit 580 of the decryption apparatus 500 transmits “ext_info1 = GID01” and “date = 20170302” to the decryption key generation apparatus 400 as the environment information α.

  The decryption key generation unit 410 of the decryption key generation device 400 generates the decryption key sk from the environment information α′′ext_info1 = GID01 ′ ′ and “date = 20170302 ′ ′ and the master key mk. The transmission / reception unit 480 of the decryption key generation device 400 transmits the decryption key sk to the decryption device 500.

  The decryption unit 520 of the decryption apparatus 500 decrypts the ciphertext D using the decryption key sk. In this case, the decryption condition c is {(ext_info1 = GID01) OR (ext_info1 = GID02)} AND (date = 20170302), and the decryption key is generated from the environment information α "ext_info1 = GID01" and "date = 020170302" The plaintext is correctly decrypted because On the other hand, for example, when the decryption key sk is generated with the environment information α as “ext_info1 = GID04” and “date = 20170302”, the decryption unit 520 does not make sense because the decryption condition c is not satisfied. It will generate a value.

  Thus, while defining the use of the extended attribute ID that was undefined at the setup processing time in the encryption option information and defining the specification method of acquiring the attribute value in the encryption option information, the extended attribute is defined. Since the ID can be used to specify a decryption condition, there is no need to regenerate system parameters or modify the system.

  As in the example described here, one extended attribute ID can be used multiple times to describe encryption option information.

  In addition, if an external web server that can be trusted is specified as an acquisition destination, it becomes possible to acquire a value that is more reliable than a value acquired by a predetermined method.

  When an external Web server which is an acquisition destination holds a plurality of attribute values, auxiliary information may be specified as encryption option information in order to specify which one of them is to be acquired. For example, for time information that varies depending on the area, specifying the area name as supplementary information and acquiring the value of the attribute “time information” makes it possible to acquire time information of the area. .

[Others]
By giving encryption option information as header information of encryption data, a ciphertext can be generated as a set of encryption data and encryption option information. In this case, the header information may be analyzed and the encryption option information may be falsified. In the case of tampering, acquisition of environment information unintended by the user of the cryptographic device 300 may be performed, and generation of a decryption key unintended by the user may be performed.

  Therefore, when tampering of the encryption option information is detected, a function to stop the decryption processing is added to prevent unauthorized decryption due to the tampering. The tampering detection function can be realized, for example, using a hash value. When the ciphertext generation unit 310 of the encryption apparatus 300 generates a ciphertext, a hash value of the encryption option information is taken together with the encryption option information, and is added to the encrypted data to generate a ciphertext. The environment information acquisition unit 510 of the decryption apparatus 500 verifies from the encryption option information included in the ciphertext and the hash value whether the encryption option information has been tampered with. If it is tampered with, the process is stopped, and if it is not tampered with, environmental information is acquired as described above. By doing this, it is possible to prevent the generation of the decryption key that the user of the encryption device 300 does not intend.

  According to the present invention, by using the encryption option information, it is possible to add an attribute ID and an attribute value acquiring method without modifying the system.

<Supplementary Note>
The apparatus according to the present invention is, for example, an input unit to which a keyboard or the like can be connected, an output unit to which a liquid crystal display or the like can be connected as a single hardware entity, or a communication apparatus (eg, communication cable) capable of communicating outside the hardware entity. Communication unit that can be connected, CPU (central processing unit, cache memory, registers, etc. may be provided), RAM or ROM that is memory, external storage device that is hard disk, input unit for these, output unit, communication unit , CPU, RAM, ROM, and a bus connected so as to enable exchange of data between external storage devices. If necessary, the hardware entity may be provided with a device (drive) capable of reading and writing a recording medium such as a CD-ROM. Examples of physical entities provided with such hardware resources include general purpose computers.

  The external storage device of the hardware entity stores a program necessary for realizing the above-mentioned function, data required for processing the program, and the like (not limited to the external storage device, for example, the program is read) It may be stored in the ROM which is a dedicated storage device). In addition, data and the like obtained by the processing of these programs are appropriately stored in a RAM, an external storage device, and the like.

  In the hardware entity, each program stored in the external storage device (or ROM etc.) and data necessary for processing of each program are read into the memory as necessary, and interpreted and processed appropriately by the CPU . As a result, the CPU realizes predetermined functions (each component requirement expressed as the above-mentioned,...

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Further, the processing described in the above embodiment may be performed not only in chronological order according to the order of description but also may be performed in parallel or individually depending on the processing capability of the device that executes the processing or the necessity. .

  As described above, when the processing function in the hardware entity (the apparatus of the present invention) described in the above embodiment is implemented by a computer, the processing content of the function that the hardware entity should have is described by a program. Then, by executing this program on a computer, the processing function of the hardware entity is realized on the computer.

  The program describing the processing content can be recorded in a computer readable recording medium. As the computer readable recording medium, any medium such as a magnetic recording device, an optical disc, a magneto-optical recording medium, a semiconductor memory, etc. may be used. Specifically, for example, as a magnetic recording device, a hard disk device, a flexible disk, a magnetic tape or the like as an optical disk, a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only) Memory), CD-R (Recordable) / RW (Rewritable), etc. as magneto-optical recording medium, MO (Magneto-Optical disc) etc., as semiconductor memory EEP-ROM (Electronically Erasable and Programmable Only Read Memory) etc. Can be used.

  Further, this program is distributed, for example, by selling, transferring, lending, etc. a portable recording medium such as a DVD, a CD-ROM or the like in which the program is recorded. Furthermore, this program may be stored in a storage device of a server computer, and the program may be distributed by transferring the program from the server computer to another computer via a network.

  For example, a computer that executes such a program first temporarily stores a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. Then, at the time of execution of the process, the computer reads the program stored in its own recording medium and executes the process according to the read program. Further, as another execution form of this program, the computer may read the program directly from the portable recording medium and execute processing according to the program, and further, the program is transferred from the server computer to this computer Each time, processing according to the received program may be executed sequentially. In addition, a configuration in which the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes processing functions only by executing instructions and acquiring results from the server computer without transferring the program to the computer It may be Note that the program in the present embodiment includes information provided for processing by a computer that conforms to the program (such as data that is not a direct command to the computer but has a property that defines the processing of the computer).

  Further, in this embodiment, the hardware entity is configured by executing a predetermined program on a computer, but at least a part of the processing content may be realized as hardware.

Claims (7)

M, N is an integer of 1 or more, Standard attribute ID is an attribute ID whose application is already defined, Extended attribute ID is an attribute ID whose application is undefined, attribute ID list is M standard attribute IDs and N pieces A list of extended attribute IDs,
A cryptographic processing system including a system parameter generation device, an encryption device, a decryption key generation device, and a decryption device is a cryptographic processing method for performing encryption and decryption,
The encryption device records public parameters generated by the system parameter generation device from the attribute ID list,
The decryption key generation device records a master key generated by the system parameter generation device from the attribute ID list,
A logical expression in which a primitive logical expression using a standard attribute ID or an extended attribute ID included in the attribute ID list as a decryption condition is connected by a logical operator, an encryption ID information is included in the attribute ID list Information to be specified using
A ciphertext generation step of generating a ciphertext from the plaintext, the decryption condition, and the encryption option information using the public parameter;
The attribute ID used in the decryption condition used for generating the ciphertext and the value thereof using the encryption option information used for generating the ciphertext received from the encryption device by the decryption device An environmental information acquisition step of acquiring environmental information which is
A decryption key generation step of the decryption key generation device generating a decryption key from the environment information received from the decryption device and the master key;
A decryption step of decrypting the ciphertext by using the decryption key received from the decryption key generation device by the decryption device. The encryption processing method according to claim 1, wherein
The encryption processing method according to claim 1, wherein the encryption option information includes a description defining an application of the extended attribute ID. The encryption processing method according to claim 1 or 2, wherein
The encryption processing method, wherein the encryption option information includes a description specifying a method of acquiring an attribute value of the attribute ID. M, N is an integer of 1 or more, Standard attribute ID is an attribute ID whose application is already defined, Extended attribute ID is an attribute ID whose application is undefined, attribute ID list is M standard attribute IDs and N pieces A list of extended attribute IDs,
A logical expression in which a primitive logical expression using a standard attribute ID or an extended attribute ID included in the attribute ID list as a decryption condition is connected by a logical operator, an encryption ID information is included in the attribute ID list Information to be specified using
An encryption processing system including a system parameter generation device, an encryption device, a decryption key generation device, and a decryption device,
The encryption device is
A recording unit that records the public parameter generated by the system parameter generation device from the attribute ID list;
A ciphertext generation unit that generates a ciphertext from the plaintext, the decryption condition, and the encryption option information using the public parameter;
The decryption key generation device
A recording unit that records the master key generated by the system parameter generation device from the attribute ID list;
A decryption key generation unit that generates a decryption key from the environment information received from the decryption apparatus and the master key;
The decoding device is
The attribute ID used in the decryption condition used in the generation of the ciphertext using the encryption option information used for generation of the ciphertext received from the encryption device, and the environment information that is the value thereof The environmental information acquisition unit to acquire
An encryption processing system including a decryption unit that decrypts the ciphertext using the decryption key received from the decryption key generation device.   The encryption apparatus contained in the encryption processing system of Claim 4.   A decryption apparatus included in the cryptographic processing system according to claim 4.   A program for causing a computer to function as any one of the encryption device according to claim 5 and the decryption device according to claim 6.

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