JP2006352316A - Privacy protection encryption method, privacy protection encryption system, and privacy protection encryption program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a privacy protection encryption method, a privacy protection encryption system, and a privacy protection encryption program for employing a contrivance capable of warranting no matching of a public key leading to particularization of an individual in the case of encryption by using an asymmetric key encryption and information being an encryption object between encryption executing parties at the same time. <P>SOLUTION: The privacy protection encryption system realizes a configuration such that commutative public key encryption means 203 are utilized to separate encryption executing parties into an asymmetric encryption encrypting apparatus 200 for an intermediate agent and into an asymmetric key encryption encrypting apparatus 400 for a primary information provider so that the public key and encryption object information are not matched between the respective encryption executing parties. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an encryption method, an encryption system, and an encryption program, and in particular, an encryption method, an encryption system, and an encryption method that avoid a privacy problem caused by a combination of information to be encrypted and an asymmetric encryption key owner. Related to the program.

  Encryption is a technique that has been used mainly for concealing communication contents. On the other hand, while the demand for protecting personal information is increasing, there is a risk that even encrypted information is treated as information that can identify an individual, that is, a privacy problem. For example, when encryption is performed with a public key of asymmetric key encryption, the public key itself can be regarded as information that can identify an individual. This is especially true when it is proved by a public key certificate. When encrypting using such a public key, a cryptographer who has both the public key and the information to be encrypted can link the individual with the information to be encrypted, and privacy There is a risk of problems.

  In particular, there is a possibility that a recording medium on which information is written may be read by a third party, for example, an RFID tag (hereinafter simply referred to as a tag), as a privacy problem of encrypted information has been pointed out. There is). As described in Non-Patent Document 1, three types of information that may lead to a privacy threat include information on a database, tag user data area information, and tag ID information. Focusing on the privacy protection of the user data area information of the tag in particular, even Non-Patent Document 1 can take measures by encrypting.

  However, simply encrypting it is effective for referring to unnecessary tags from third parties (privacy infringement), but for database administrators and those involved in the distribution stage, user information Since at least both the public key of the asymmetric encryption and the original information to be encrypted may be known, even if the encryption is performed, the user can be associated with the original information to be encrypted, resulting in a privacy problem. For this reason, privacy cannot be protected unless encryption is performed by the user himself / herself or by a reliable participant. Another advantage of using a public key is that it is encrypted using a public key by others, and if the user himself / herself performs encryption using his / her public key, there are many asymmetrical features. It doesn't make sense when using key cryptography.

Shingo Kinoshita, Literary Hoshino, Tomoyuki Komuro, Akiko Fujimura, Miyako Okubo, Low Cost RFID Privacy Protection Law, Information Processing Society of Japan, Information Processing Society of Japan, Vol. 45, No. 8, August 15, 2004, pp. 2007-2021

  The first problem is that when encryption is performed using asymmetric key cryptography, the user's public key corresponds to information that can identify an individual. This means that information that can be specified must exist at the same time.

  The second problem is that information related to the user, such as the user's public key, and information to be encrypted are prepared for others who perform encryption using asymmetric key encryption. If you ask someone else, you must be a reliable person.

  The third problem is that in order to secure the time and place of encryption, it is necessary for the user himself / herself to perform it in a safe environment. Therefore, in order to ensure safety at the time of encryption using asymmetric key cryptography, the user There is a burden of having to have a device or the like having an encryption function.

  Accordingly, the object of the present invention is to guarantee that the public key and the information to be encrypted that are associated with identifying an individual when encryption is performed using asymmetric key cryptography are not provided to the cryptographer at the same time. According to the mechanism, a privacy protection encryption method, a privacy protection encryption system, and a privacy protection encryption program are provided.

  In order to solve the above problems, the present invention employs means for solving the problems having the following characteristics.

  The privacy protection encryption system of the present invention encrypts encrypted information from a primary information provider with a user information input means for inputting a user encryption request and a user public key, and the user public key. Commutative public-key encryption / encryption means, and intermediate trader control means for controlling communication with a primary information provider, writing to a recording medium writing device, and processing in an asymmetric encryption encryption device for an intermediate trader A middle-tier contractor, an encryption target information input means for inputting information to be encrypted, an intermediate request for encryption and exchange of encryption information with a communication device, input of encryption target information and encryption The primary information provider's control means for controlling the processing in the asymmetric encryption encryption device for the primary information provider, such as encryption or decryption processing, and the encryption target information and its own public key are used for encryption or intermediate Exchangeable public key encryption information received from a vendor It consists of a primary information provider equipped with a commutative public key encryption means that decrypts with its own private key, and the user makes an encryption request to the intermediate company, and the intermediate company sends the information to be encrypted. The primary information provider who receives the encryption request sends the encrypted information with its own public key to the intermediate contractor using commutative public key cryptography. The trader further encrypts the encrypted information from the primary information provider with the public key of the user using the exchangeable public key cryptography, and sends the encrypted information to the primary information provider. The primary information provider decrypts what has been encrypted with the user's public key, further encrypted with the user's public key, and sends it to the intermediate agent. In response, the intermediate contractor operates to write on a recording medium to be delivered to the user.

  In this way, the encryption entity is divided into two parties, the middleman and the primary information provider, and the user's public key, which is information about the user, is separated from the encryption target information. Therefore, it is possible to achieve the object of the present invention to avoid the privacy problem caused by the connection between the user and the information to be encrypted.

  By using the present invention, the primary information provider has information to be stored, but cannot have information about the user (such as the user's public key). Link (link) with information before encryption and storage on a medium (RFID, IC card, USB memory, magnetic tape, magnetic disk, magneto-optical disk, optical disk, medium capable of digital recording such as communication) The encrypted information can be safely stored on the recording medium while protecting the privacy.

  Further, according to the present invention, the intermediate contractor has information about the user (such as the user's public key), but cannot have the information before encryption of the encrypted information stored in the recording medium. In addition, it is not possible for the intermediate trader to link (link) the user with the information before being encrypted and stored in the recording medium, and the encrypted information can be safely stored in the recording medium in a state where privacy is protected.

  In addition, according to the present invention, neither the primary information provider nor the intermediary company can link (link) the information before being encrypted and stored in the recording medium with the information about the user (such as the user's public key). It is safe to use an encryption device or a writing device for a recording medium owned by an intermediate contractor. Therefore, the user can safely store the encryption information in the recording medium without having an encryption device or a writing device for the recording medium.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings.

  Referring to FIG. 1, the first embodiment of the present invention is a user information holding device 100, an asymmetric key encryption / encryption device 200 for a middleman, a user information input unit 201, and a middleman control unit. 202, commutative public key encryption / encryption means 203, communication apparatus 300, asymmetric key encryption / encryption apparatus 400 for primary information provider, encryption target information input means 401, and control means for primary information provider 402, an encryption target information holding device 500, and a recording medium writing device 600.

  The asymmetric key encryption / encryption device 200 for an intermediate contractor includes a user information input unit 201, an intermediate contractor control unit 202, and a replaceable public key encryption / encryption unit 203.

  The asymmetric key encryption / encryption device 400 for the primary information provider includes an encryption target information input unit 401, a primary information provider control unit 402, and a replaceable public key encryption / encryption unit 203.

  The communication device 300 serves to separate the asymmetric key encryption / encryption device 200 for intermediate traders and the asymmetric encryption / encryption device 400 of the primary information provider, and to exchange information therebetween.

  Each of these means operates as follows. The user information input means 201 inputs the encryption request from the user and the user's public key from the user input holding device 100 and passes them to the middleman control means 202.

  Based on a request from the user information input unit 201, the intermediate trader control unit 202 sends an encryption request to the primary information provider asymmetric key encryption / encryption device 400 through the communication device 300, or provides primary information. The encrypted information by the public key of the primary information provider from the asymmetric key encryption apparatus 400 for the user is received and passed to the exchangeable public key encryption means 203 together with the public key of the user, or for the primary information provider Information obtained by encrypting the encrypted information by the public key with the user's public key is received from the exchangeable public key encryption unit 203 and passed to the asymmetric key encryption / encryption device 400 for the primary information provider through the communication device 300, The information encrypted with the public key of the user from the asymmetric key encryption / encryption device 400 for the primary information provider is received and sent to the recording medium writing device 600.

The exchangeable public key encryption / encryption means 203 is an encryption means using exchangeable public key encryption. The commutative public key encryption is an asymmetric key encryption having the following properties. The encryption key is K, and the message M encrypted with the key K is written as E_K (M). At this time, the commutative public key cipher is based on an arbitrary message M and two keys K1 and K2.
E_K1 (E_K2 (M)) = E_K2 (E_K1 (M))
It is an encryption system that satisfies For example, RSA encryption has this property.

  Also, because the encryption and decryption processes are the same due to the characteristics of public key cryptography, the commutative public key encryption / encryption means 203 performs encryption using a plaintext and a public key to generate a ciphertext. Or processing with ciphertext and secret key and decryption back to plaintext.

  The encryption target information input unit 401 takes in the information to be encrypted from the encryption target information holding device 500 and passes it to the primary information provider control unit 402 in response to a request from the primary information provider control unit.

  The primary information provider control unit 402 receives the encryption request from the asymmetric key encryption / encryption device 200 for the middle trader through the communication device 300, and the encryption target information and the primary information provider from the encryption target information input unit 401. The public key is transferred to the exchangeable public key encryption unit 203, or the encrypted information by the public key of the primary information provider is received from the exchangeable public key encryption encryption unit 203, and the asymmetric key for the middleman is received through the communication device 300. Provision of information and primary information obtained by passing the encrypted information with the public key for the primary information provider from the asymmetric key encryption / encryption device 200 for the middleman to the encryption / encryption device 200 and further encrypting the encrypted information with the public key of the user The user's private key is passed to the exchangeable public key encryption / encryption means 203, and the information encrypted with the user's public key from the exchangeable public key encryption / encryption means 203 is transferred to the communication device 300. And or to an asymmetric key cryptography encryption device 200 for intermediaries to.

  Next, the overall operation of this embodiment will be described in detail with reference to the timing charts of FIGS. 1 and 2 and the flowcharts of FIGS. 3, 4, 5, 6, and 7.

  First, at the start of processing, processing related to an encryption request (step A in FIG. 2) is performed. Specifically, the encryption request is detected (step 1001 in FIG. 3). Acquisition of user information and the like (user's public key Ku1 and the like) (step 1002). Transmit primary information request (step 1003).

  Next, the information M is encrypted (step D in FIG. 2). Specifically, the primary information request is detected (step 1004 in FIG. 4). Capture of encryption target information M (step 1005). Commutable public key encryption process (E_Ks1 (M), Ks1 is the public key of the primary information provider) (step 1006). Transmission of encrypted information using the public key of the primary information provider (step 1007).

  Further, encryption processing using the user public key (step B in FIG. 2). Specifically, detection of encrypted information using the public key of the primary information provider (step 1008 in FIG. 5). Commutable public key encryption processing (E_Ku1 (E_Ks1 (M))) (step 1009). Transmission of re-encrypted information (step 1010).

  Further, a decryption process using the private key of the primary information provider (step E in FIG. 2). Specifically, re-encryption information is detected (step 1011 in FIG. 6). A commutative public key encryption / decryption process (decryption process) (E_Ks2 (E_Ku1 (E_Ks1 (M))), Ks2 is the private key of the primary information provider) (step 1012). Transmission of encryption information (E_Ku1 (M) as a result of the decryption process) using the user public key (step 1013).

  Finally, a process of writing the encrypted information to the recording medium using the user public key (step C in FIG. 2). Specifically, detection of encrypted information by the user public key is performed (step 1014 in FIG. 7). Writing encrypted information (E_Ku1 (M)) to the recording medium using the user public key (step 1015).

  Next, the effect of this embodiment will be described. In the present embodiment, the asymmetric encryption / encryption device 200 for the intermediate trader and the asymmetric encryption / encryption device 400 for the primary information provider are configured with the communication device 300 therebetween, so that the public key of the user Of the two data of the encryption target information M, the user's public key is stored in the asymmetric encryption encryption apparatus 200 for the intermediate trader, and the encryption target information M is stored in the asymmetric encryption encryption apparatus 400 for the primary information provider. Since it is possible to handle the other data but not the other data, it is possible to avoid the privacy problem caused by the two pieces of data when the user's public key corresponds to personal information.

  Next, the best mode for carrying out the second invention of the present invention will be described in detail with reference to the drawings.

  Referring to FIG. 8, in the second embodiment of the present invention, a user information holding device 100, an asymmetric key encryption / encryption device 210 for a middleman, a user information input unit 211, and a control unit for a middleman. 212, commutative public key encryption / encryption means 203, communication apparatus 300, asymmetric key encryption / encryption apparatus 410 for encryption service provider, encryption service provider control means 411, and recording medium writing apparatus 600. It consists of and.

  An asymmetric key encryption / encryption device 210 for an intermediate contractor includes a user information input unit 211, an intermediate contractor control unit 212, and a replaceable public key encryption / encryption unit 203. The asymmetric key encryption / encryption device 410 for the encryption service provider includes an encryption service provider control unit 411 and a replaceable public key encryption / encryption unit 203. The communication device 300 serves to separate the asymmetric key encryption / encryption device 210 for the middleman and the asymmetric encryption / encryption device 410 for the encryption service provider, and to exchange information therebetween.

  Each of these means operates as follows. The user information input means 201 receives from the user input holding device 100 the encryption request from the user, the user's public key, and the information that the user has already encrypted using the public key of the encryption service provider. These are input and passed to the middleman control means 212.

  Based on a request from the user information input unit 211, the intermediate trader control unit 212 converts the encrypted information using the public key of the encryption service provider with the public key of the user so that the information is exchangeable public key. Information that is passed to the encryption / encryption means 203 or re-encrypted with the public key of the user from the information encrypted with the public key of the encryption service provider is received from the exchangeable public key encryption means 203 and passed through the communication device 300. The recording medium writing device 600 receives information encrypted with the public key of the user from the asymmetric key encryption / encryption device 410 for the encryption service provider or passed to the asymmetric key encryption / encryption device 410 for the encryption service provider. Or send to.

The exchangeable public key encryption / encryption means 203 is an encryption means using exchangeable public key encryption. The commutative public key encryption is an asymmetric key encryption having the following properties. The encryption key is K, and the message M encrypted with the key K is written as E_K (M). At this time, the commutative public key cipher is based on an arbitrary message M and two keys K1 and K2.
E_K1 (E_K2 (M)) = E_K2 (E_K1 (M))
It is an encryption system that satisfies For example, RSA encryption has this property.

  Also, because the encryption and decryption processes are the same due to the characteristics of public key cryptography, the commutative public key encryption / encryption means 203 performs encryption using a plaintext and a public key to generate a ciphertext. Or processing with ciphertext and secret key and decryption back to plaintext.

  The encryption service provider control means 411 further encrypts the encryption information by the public key for the encryption service provider from the asymmetric key encryption encryption apparatus 210 for the middleman through the communication device 300 with the public key of the user. The information and the private key of the encryption service provider are transferred to the exchangeable public key encryption / encryption means 203, or the information encrypted with the user's public key from the exchangeable public key encryption / encryption means 203 is transmitted to the communication apparatus 300. To the asymmetric key encryption / encryption device 210 for the intermediate trader.

  Next, the overall operation of this embodiment will be described in detail with reference to the timing charts of FIGS. 8 and 9 and the flowcharts of FIGS. 11, 12, and 13.

  First, at the start of processing, processing related to an encryption request (step F in FIG. 9) is performed. Specifically, the encryption request is detected (step 1101 in FIG. 10). Fetching encrypted information (E_Ks1 (M)) using user information and the like (user's public key Ku1 and the like) and the cryptographic service provider's public key (step 1202). Commutable public key encryption processing (E_Ku1 (E_Ks1 (M))) (step 1103). Transmission of re-encrypted information (step 1104).

  Next, a decryption process using the secret key of the encryption service provider provider (step H in FIG. 9). Specifically, re-encryption information is detected (step 1105 in FIG. 11). A commutative public key encryption / decryption process (decryption process) (E_Ks2 (E_Ku1 (E_Ks1 (M))), Ks2 is the private key of the primary information provider) (step 1106). Transmission of encryption information (E_Ku1 (M) as a result of the decryption process) using the user public key (step 1107).

  Finally, a process for writing the encrypted information to the recording medium using the user public key (step G in FIG. 9). Specifically, detection of encrypted information by the user public key is performed (step 1108 in FIG. 12). Writing encrypted information (E_Ku1 (M)) to the recording medium using the user public key (step 1109).

  Next, the effect of this embodiment will be described.

  In the present embodiment, the asymmetric encryption / encryption device 210 for the middleman and the asymmetric encryption / encryption device 410 for the encryption service provider are configured to be separated from the communication device 300. Of the two pieces of data to be encrypted M, the user's public key is used in the asymmetric encryption encryption device 210 for the middleman, and the encryption target information M in the asymmetric encryption encryption device 410 for the encryption service provider. Since both of the user's public keys cannot be handled directly, it is possible to avoid a privacy problem caused by two pieces of data when the user's public key corresponds to personal information.

  Next, the best mode for carrying out the third invention of the present invention will be described in detail with reference to the drawings.

  Referring to FIG. 13, the third embodiment of the present invention relates to a user information holding device 100, an asymmetric key encryption / encryption device 200 for a middleman, a user information input unit 201, and a middleman control unit. 202, commutative public key encryption / encryption means 203, communication apparatus 300, asymmetric key encryption / encryption apparatus 420 for primary information provider, encryption target information input means 401, and control means for primary information provider 421, an information unique information stage 422, an encryption target information holding device 500, and a recording medium writing device 600.

  The asymmetric key encryption / encryption device 200 for an intermediate contractor includes a user information input unit 201, an intermediate contractor control unit 202, and a replaceable public key encryption / encryption unit 203.

  An asymmetric key encryption / encryption device 420 for a primary information provider includes an encryption target information input unit 401, a primary information provider control unit 421, an information unique information stage 422, and a replaceable public key encryption / encryption unit. 203.

  The communication device 300 serves to separate the asymmetric key encryption / encryption device 200 for intermediate traders and the asymmetric encryption / encryption device 420 of the primary information provider, and exchange information therebetween.

  Each of these means generally operates as follows.

  The user information input means 201 inputs the encryption request from the user and the user's public key from the user input holding device 100 and passes them to the middleman control means 202.

  Based on a request from the user information input unit 201, the intermediate trader control unit 202 sends an encryption request to the primary information provider asymmetric key encryption / decryption device 420 through the communication device 300, or provides primary information. The encrypted information by the public key of the primary information provider from the asymmetric key encryption / encryption device 420 for the user is received and passed to the exchangeable public key encryption / encryption means 203 together with the public key of the user, or for the primary information provider Information obtained by encrypting the encrypted information by the public key with the user's public key is received from the exchangeable public key encryption unit 203 and passed to the asymmetric key encryption / encryption device 420 for the primary information provider through the communication device 300, The information encrypted with the public key of the user from the asymmetric key encryption / encryption device 420 for the primary information provider is received and sent to the recording medium writing device 600.

The exchangeable public key encryption / encryption means 203 is an encryption means using exchangeable public key encryption. The commutative public key encryption is an asymmetric key encryption having the following properties. The encryption key is K, and the message M encrypted with the key K is written as E_K (M). At this time, the commutative public key cipher is based on the arbitrary message M and the two keys K1 and K2.
E_K1 (E_K2 (M)) = E_K2 (E_K1 (M))
It is an encryption system that satisfies For example, RSA encryption has this property.

  Also, because the encryption and decryption processes are the same due to the characteristics of public key cryptography, the commutative public key encryption / encryption means 203 performs encryption using a plaintext and a public key to generate a ciphertext. Or processing with ciphertext and secret key and decryption back to plaintext.

  The encryption target information input unit 401 takes in the information to be encrypted from the encryption target information holding device 500 in response to a request from the primary information provider control unit and passes it to the primary information provider control unit 421.

  The primary information provider control unit 421 receives the encryption request from the asymmetric key encryption / encryption device 200 for the middle trader through the communication device 300, and converts the encryption target information from the encryption target information input unit 401 into unique information. The information to the encryption means 422, the unique encryption target information from the information unique information means 422 and the public key of the primary information provider to the exchangeable public key encryption means 203, the exchangeable public key encryption The encrypted information by the public key of the primary information provider from the encryption unit 203 is received and passed to the asymmetric key encryption / encryption device 200 for the middleman through the communication device 300, or from the asymmetric key encryption / encryption device 200 for the middleman. The information obtained by further encrypting the encrypted information using the public key for the primary information provider with the public key of the user and the private key of the primary information provider are exchangeable public key encryption encryption means 20 Pass or, or to an asymmetric key cryptography encryption device 200 for the intermediate art through commutative public key cryptography encryption means 203 user encrypted information communication device 300 with the public key from the.

  The information unique information converting means 422 receives the encryption target information from the primary information provider control means 421, converts it into unique information, and returns it to the primary information provider control means 421. If the information to be encrypted is always the same, the encrypted information will always be the same, increasing the risk of being identified. In order to avoid this, the encryption target information always has a different value. For example, a serial number or a random number is added to the encryption target information so that the encryption target information is always different.

  Next, the overall operation of this embodiment will be described in detail with reference to the timing charts of FIGS. 13 and 14 and the flowcharts of FIGS. 3, 15, 5, 6, and 7.

  First, at the start of processing, processing related to an encryption request (step A in FIG. 14) is performed. Specifically, the encryption request is detected (step 1001 in FIG. 3). Acquisition of user information and the like (user's public key Ku1 and the like) (step 1002). Transmit primary information request (step 1003).

  Next, the information M is encrypted (step J in FIG. 14). Specifically, the primary information request is detected (step 1201 in FIG. 15). Capture of encryption target information N (step 1202). A unique information conversion process for changing the encryption target information N into unique information M (step 1203). Commutable public key encryption processing (E_Ks1 (M), Ks1 is the public key of the primary information provider) (step 1204). Transmission of encrypted information using the public key of the primary information provider (step 1205).

  Further, encryption processing using the user public key (step B in FIG. 14). Specifically, detection of encrypted information using the public key of the primary information provider (step 1008 in FIG. 5). Commutable public key encryption processing (E_Ku1 (E_Ks1 (M))) (step 1009). Transmission of re-encrypted information (step 1010).

  Further, a decryption process using the private key of the primary information provider (step E in FIG. 14). Specifically, re-encryption information is detected (step 1011 in FIG. 6). A commutative public key encryption / decryption process (decryption process) (E_Ks2 (E_Ku1 (E_Ks1 (M))), Ks2 is the private key of the primary information provider) (step 1012). Transmission of encryption information (E_Ku1 (M) as a result of the decryption process) using the user public key (step 1013).

  Finally, a process for writing the encrypted information to the recording medium using the user public key (step C in FIG. 14). Specifically, detection of encrypted information by the user public key is performed (step 1014 in FIG. 7). Writing encrypted information (E_Ku1 (M)) to the recording medium using the user public key (step 1015).

  Next, the effect of this embodiment will be described. In the present embodiment, the asymmetric encryption / encryption device 200 for the intermediate trader and the asymmetric encryption / encryption device 420 for the primary information provider are configured with the communication device 300 separated from each other. Of the two data of the encryption target information M, the user's public key is used in the asymmetric encryption encryption apparatus 200 for the intermediate trader, and the encryption target information M is stored in the asymmetric encryption encryption apparatus 420 for the primary information provider. Since it is possible to handle the other data but not the other data, it is possible to avoid the privacy problem caused by the two pieces of data when the user's public key corresponds to personal information. In addition, since processing is performed in the asymmetric encryption encryption apparatus 420 for the primary information provider so that the encryption target information M always has a different value, it is possible to avoid a specific problem due to the encrypted information.

  Further, each of the above-described embodiments is merely an example of a preferred embodiment of the present invention, and the present invention can be implemented with various modifications without departing from the gist thereof.

  As a fourth embodiment, in addition to the devices described in the above embodiments, a recording medium recording a computer program for causing a computer to execute the above privacy protection encryption method is provided. This recording medium may be either a portable type or a fixed type, and may be a magnetic disk, a semiconductor memory, a CD-ROM or other recording medium. In addition, a computer program for executing this data analysis method can be stored in a recording device of a computer connected to a network, and transferred to another computer via the network. The providing medium for providing the computer program for executing the privacy protection encryption method can be distributed as a computer-readable medium in various formats, and is not limited to a specific type of medium. .

  The privacy protection encryption program is read from the recording medium into the encryption device, controls the operation of the encryption device, and executes the same processing as the privacy protection encryption processing in the first to third embodiments.

[Example]
Next, the operation of the best mode for carrying out the present invention will be described using specific examples. As shown in FIG. 13, when storing the information E_Ku1 (E) obtained by encrypting the information M with the user's public key Ku1 in the RFID tag, it is also implemented in the server by carrying out using the first invention described above. It is possible to perform encryption that protects privacy without having both the information M and the public key of the user even for the middleman.

  INDUSTRIAL APPLICABILITY According to the present invention, the present invention can be applied to a public key encryption application when it is desired to avoid a privacy problem caused by a public key and encryption target information being combined in a public key encryption scene. For example, when storing information in the RFID tag as encryption information for privacy protection when the RFID tag is referred to, a privacy problem caused by a combination of the public key generated at the time of encryption and the information to be encrypted You can encrypt while avoiding.

  In addition, as shown in the second invention, by publicizing the public key of the encryption service provider widely and performing the encryption in advance, a person who always decrypts the information to be encrypted by the commutative public key encryption. Without having it, it is possible to provide a service that performs privacy protection encryption.

[BRIEF DESCRIPTION OF THE DRAWINGS] It is a block diagram which shows the structure of the best form for implementing 1st invention of this invention. It is a sequence chart which shows the operation | movement of the best form for implementing 1st invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 1st invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 1st invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 1st invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 1st invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 1st invention. It is a block diagram which shows the structure of the best form for implementing 2nd invention of this invention. It is a sequence chart which shows the operation | movement of the best form for implementing 2nd invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 2nd invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 2nd invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 2nd invention. It is a block diagram which shows the structure of the best form for implementing 3rd invention of this invention. It is a sequence chart which shows the operation | movement of the best form for implementing 3rd invention. It is a flowchart which shows a part of operation | movement of the best form for implementing 3rd invention. It is a figure for demonstrating the structure and operation | movement of the best form for implementing 1st invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 User information holding apparatus 200 Asymmetric key encryption encryption apparatus for intermediate contractors 201 User information input means 202 Control means for intermediate contractors 203 Exchangeable public key encryption encryption means 210 Asymmetric key encryption encryption apparatus for intermediate contractors 211 User information input means 212 Intermediary control means 300 Communication apparatus 400 Asymmetric key encryption / encryption apparatus for primary information provider 401 Encryption target information input means 402 Primary information provider control means 410 Asymmetric for encryption service provider Key encryption / encryption device 411 Encryption service provider control unit 421 Primary information provider control unit 422 Information unique information generation unit 500 Encryption target information holding unit 600 Recording medium writing unit

Claims (26)

User information input means for inputting an encryption request from a user and a user public key, control means for an intermediary for controlling input and output, encryption and communication, and commutative public key encryption and encryption means An asymmetric key encryption / encryption device for an intermediary that receives the user's encryption request, captures user information, and transmits a primary information request;
An encryption target information input means for inputting information to be encrypted, a primary information provider control means for controlling input and output, encryption and communication, and a commutative public key encryption encryption means, Performs encryption processing with the public key for the primary information provider on the captured information to be encrypted, transmits the public key encryption information for the primary information provider, and asymmetric key encryption encryption for the intermediary Primary information provider that receives re-encrypted information from the device, decrypts it with a private key for the primary information provider, and sends the user public key encrypted information encrypted with the user public key An asymmetric cryptographic encryption device for
A communication device for connecting the asymmetric encryption encryption device for the intermediate trader and the asymmetric encryption encryption device for the primary information provider via a communication network;
A privacy protection encryption system characterized by comprising: User information input means for inputting an encryption request from the user and the public key of the user, control means for an intermediary for controlling input and output, encryption and communication, and commutative public key encryption and encryption means; And receiving the user's encryption request, fetching the user information and encryption information using the public key of the encryption service provider, and subjecting it to a commutative public key cryptography process using the user's public key. An asymmetric key encryption / encryption device for an intermediary that transmits the re-encryption information,
A cryptographic service provider control means for controlling communication and encryption of the cryptographic service provider, and a commutative public key cryptographic encryption means, receives the re-encryption information, and receives the re-encryption information for the cryptographic service provider. An asymmetric encryption encryption device for an encryption service provider that performs decryption processing with a private key and transmits user public key encryption information encrypted with the user public key;
A communication device for connecting the asymmetric encryption / encryption device for the middleman and the asymmetric encryption / encryption device for the encryption service provider via a communication network;
A privacy protection encryption system characterized by comprising:   2. The privacy protection encryption system according to claim 1, wherein the asymmetric key encryption / encryption device for the primary information provider includes unique information converting means for adding a serial number or a random number to the encryption target information.   The privacy protection encryption system according to any one of claims 1 to 3, further comprising means for writing the encryption information to a recording medium. Detecting an encryption request input by a user;
Capturing user information when the encryption request is detected;
Transmitting a primary information request to an encryption device for a primary information provider;
Detecting the primary information request;
Capturing the encryption target information when the primary information request is detected; and
Performing encryption processing on the captured encryption target information using the public key of the primary information provider;
Transmitting the encrypted encryption information;
Receiving the encrypted encrypted information and re-encrypting the information with a user public key;
Transmitting the re-encrypted re-encrypted information;
Decrypting the re-encrypted information with the primary information provider's private key;
Transmitting encrypted information by a user public key that is a result of the decryption process;
Writing encrypted information by the user public key to a recording medium,
A privacy-protecting encryption method, wherein encryption is performed without having a user's public key and encryption information at the time of encryption. Detecting an encryption request input by a user;
Fetching user information and encryption information based on the public key of the encryption service provider when the encryption request is detected;
Encrypting the captured encryption information with a user's public key;
Transmitting the re-encrypted user public key encryption information;
Detecting the user public key encryption information;
When the primary information request is detected, the user public key encryption information is decrypted with a cryptographic service provider's private key;
Transmitting encrypted information by a user public key that is a result of the decryption process;
Writing encrypted information by the user public key to a recording medium,
A privacy-protecting encryption method, wherein encryption is performed without having a user's public key and encryption information at the time of encryption.   6. The privacy protection encryption method according to claim 5, further comprising a step of adding a serial number or a random number to the encryption target information in advance in order to prevent the encryption target information from becoming the same encryption information. A program that causes a computer to execute an encryption process without having a user's public key and encryption information at the time of encryption,
Detecting an encryption request input by a user;
Capturing user information when the encryption request is detected;
Transmitting a primary information request to an encryption device for a primary information provider;
Detecting the primary information request;
Capturing the encryption target information when the primary information request is detected; and
Performing encryption processing on the captured encryption target information using the public key of the primary information provider;
Transmitting the encrypted encryption information;
Receiving the encrypted encrypted information and re-encrypting the information with a user public key;
Transmitting the re-encrypted re-encrypted information;
Decrypting the re-encrypted information with the primary information provider's private key;
Transmitting encrypted information by a user public key that is a result of the decryption process;
That causes the computer to execute the program. A program that causes a computer to execute an encryption process without having a user's public key and encryption information at the time of encryption,
Detecting an encryption request input by a user;
Fetching user information and encryption information based on the public key of the encryption service provider when the encryption request is detected;
Encrypting the captured encryption information with a user's public key;
Transmitting the re-encrypted user public key encryption information;
Detecting the user public key encryption information;
When the primary information request is detected, the user public key encryption information is decrypted with a cryptographic service provider's private key;
Transmitting encrypted information by a user public key that is a result of the decryption process;
That causes the computer to execute the program. A program that causes a computer to execute an encryption process without having a user's public key and encryption information at the time of encryption,
Detecting the presence or absence of an encryption request input by a user;
Capturing the user's public key information which is user information when the encryption request is detected;
A program causing the computer to execute a step of transmitting a primary information request to an encryption device for a primary information provider. Detecting the primary information request from the encryption device for the middleman;
When detecting the primary information request, fetching the encryption target information from the encryption target information database;
Performing encryption processing on the captured encryption target information using the public key of the primary information provider using commutative public key encryption;
Transmitting encrypted information by the public key encryption of the encrypted primary information provider;
The program according to claim 10, further causing the computer to execute. Detecting the presence or absence of encrypted information by the public key of the primary information provider;
If encrypted information with the public key of the primary information provider is detected, further re-encrypting the encrypted information with the public key of the user;
The program according to claim 11, further causing the computer to execute the step of transmitting the re-encrypted re-encrypted information. Detecting the presence or absence of the re-encrypted information;
Decrypting the re-encrypted information with the primary information provider's private key if the re-encrypted information is detected;
The program according to claim 12, further causing the computer to execute a step of transmitting encryption information based on a user public key as a result of the decryption.   14. The computer according to claim 8, 9, or 13, further comprising a step of writing the encrypted information based on the user public key to a recording medium after the encrypted information based on the user public key is detected. The program according to any one. A program that causes a computer to execute an encryption process without having a user's public key and encryption information at the time of encryption,
Detecting the presence or absence of an encryption request;
Capturing information pre-encrypted with the public key of the user as the user information and the public key of the cryptographic service provider;
Further encrypting the encryption information by the public key of the cryptographic service provider using the public key of the user, using the public key of the user;
A program causing the computer to execute a step of transmitting re-encryption information as a result of the commutative public key encryption. Detecting the presence or absence of the re-encrypted information;
If the re-encrypted information is detected, decrypting the re-encrypted information with the cryptographic service provider's private key;
The program according to claim 15, further causing the computer to execute a step of transmitting encryption information based on a user public key that is a result of the commutative public key encryption.   9. The program according to claim 8, further causing the computer to execute a step of adding a serial number or a random number to the encryption target information in advance. A program that causes a computer to execute encryption processing without having the user's public key and encryption information at the time of encryption,
Detecting the presence or absence of an encryption request input by a user;
Capturing the user's public key information which is user information when the encryption request is detected;
A step of transmitting a primary information request to an encryption device for a primary information provider, detecting the presence or absence of encrypted information using the public key of the primary information provider;
If encrypted information with the public key of the primary information provider is detected, further re-encrypting the encrypted information with the public key of the user;
Transmitting the re-encrypted re-encrypted information;
A program for an intermediary that causes the computer to execute a step of writing encrypted information based on the user public key to a recording medium after the encrypted information based on the user public key is detected. A program that causes a computer to execute encryption processing without having the user's public key and encryption information at the time of encryption,
Detecting a primary information request from an intermediate device encryption device to an encryption device for a primary information provider;
When detecting the primary information request, fetching the encryption target information from the encryption target information database;
Performing encryption processing on the captured encryption target information using the public key of the primary information provider using commutative public key encryption;
Transmitting encrypted information by the public key encryption of the encrypted primary information provider;
Receiving encrypted information by the public key encryption of the transmitted primary information provider, and detecting the presence or absence of re-encrypted information that has been re-encrypted;
Decrypting the re-encrypted information with the primary information provider's private key if the re-encrypted information is detected;
A program for a primary information provider, which causes the computer to execute a step of transmitting encrypted information based on a user public key as a result of the decryption. A program that causes a computer to execute encryption processing without having the user's public key and encryption information at the time of encryption,
Detecting the presence or absence of an encryption request;
Capturing information pre-encrypted with the public key of the user as the user information and the public key of the cryptographic service provider;
Further encrypting the encryption information by the public key of the cryptographic service provider using the public key of the user, using the public key of the user;
Sending re-encrypted information that is the result of the commutative public key cryptography;
A program for an intermediary, which causes the computer to execute a step of writing encrypted information based on the user public key on a recording medium after the encrypted information based on the user public key is detected. User information input means for inputting an encryption request from the user and the public key of the user, control means for an intermediary for controlling input and output, encryption and communication, and commutative public key encryption and encryption means; With
Receiving the user's encryption request, fetching the user information and encryption information based on the public key of the cryptographic service provider, and subjecting it to the exchangeable public key cryptography process using the user's public key. Send encrypted information,
Receiving the re-encrypted information, decrypting the re-encrypted information with the private key of the primary information provider, and writing the encrypted information with the user public key as a result of the decrypting process to the recording medium Characteristic terminal device. An encryption target information input means for inputting information to be encrypted, a primary information provider control means for controlling input and output, encryption and communication, and a commutative public key encryption encryption means,
Performs encryption processing with the public key for the primary information provider on the captured information to be encrypted, transmits the public key encryption information for the primary information provider, and asymmetric key encryption encryption for the intermediary It is characterized by receiving re-encrypted information from the device, decrypting it with a private key for the primary information provider, and transmitting user public key encrypted information encrypted with the user public key. Server device. User information input means for inputting an encryption request from the user and the public key of the user, control means for an intermediary for controlling input and output, encryption and communication, and commutative public key encryption and encryption means; With
Receiving the user's encryption request, fetching the user information and encryption information based on the public key of the cryptographic service provider, and subjecting it to the exchangeable public key cryptography process using the user's public key. Send encrypted information,
Receiving the re-encryption information, decrypting the re-encrypted information with a secret key of an encryption service provider, and writing the encrypted information based on the user public key, which is the result of the decryption process, onto a recording medium A terminal device characterized by the above. A cryptographic service provider control means for controlling communication and encryption of the cryptographic service provider, and a commutative public key cryptographic encryption means,
Receives re-encrypted information obtained by performing exchangeable public key cryptography with the user's public key from the asymmetric key cryptography encryption device for the middleman, and decrypts it with the private key for the cryptographic service provider A server device that performs processing and transmits user public key encryption information encrypted with a user public key.   23. The server apparatus according to claim 22, further comprising unique information converting means for previously adding a serial number or random number to the encryption target information. A computer-readable information recording medium (compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, or semiconductor memory) characterized in that the program according to claim 8 is recorded. .)

Images