JP3889660B2 - Authentication method and authentication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for ensuring security in a computer network, and more particularly to a digital information authentication method and an authentication apparatus for executing the method.
[0002]
[Prior art]
In recent years, it has become routine to conduct business transactions via communication networks. Communication terminals used at that time range widely, such as personal computers, mobile phones, and IC cards. Along with the spread of such electronic commerce, the problem is “authentication of the other party”.
[0003]
As a representative technique for authenticating the “partner's legitimacy”, a method using “common key encryption” (hereinafter referred to as “common key encryption method”) and a method using “public key encryption” (hereinafter referred to as “common key encryption”). "Public key cryptosystem").
[0004]
For `` Common Key Cryptography '', for example, ISO / IEC99798-2.Information technology.Security techniques.Entity authentication.Part2: Mechnisms using symmetric encipherment algorithms, International Organization for Standard, 1999. and National Institute of Standards and Technology (NIST ), FIPS Publication 113: Computer Data Authentication, 1985.
[0005]
“Public Key Cryptography” is described, for example, in National Institute of Standards and Technology (NIST), FIPS Publication 186-2: Digital Signature Standard (DSS), 2000.
[0006]
The following (A) and (B) merits are given to the authentication technologies of the “common key cryptosystem” and “public key cryptosystem”.
[0007]
(A) Merits of authentication technology using `` common key cryptography ''
Since the calculation processing time is shorter than that of the “public key cryptosystem”, it is effective in authentication that requires high-speed processing.
[0008]
(B) Merits of authentication technology using “public key cryptography”
Even when there are a large number of communication terminals, it is not necessary for the authentication apparatus side to hold a key for each communication terminal in advance, so that it is not costly to manage the keys.
[0009]
[Problems to be solved by the invention]
However, on the other hand, the following problems (C) and (D) are raised in the “common key cryptosystem” and “public key cryptosystem”.
[0010]
(C) Problems with authentication technology using `` common key cryptography ''
When there are a large number of communication terminals, a different key is assigned to each communication terminal, so that the number of keys equivalent to the number of communication terminals must be held on the authentication device side, and a load is imposed on key management.
[0011]
(D) Problems with authentication technology using "public key cryptography"
When the communication terminal has limited hardware resources such as an IC card, it takes a lot of time for public key encryption processing.
[0012]
In view of the above problems, the object of the present invention is to realize the high-speed authentication processing and reduce the key management cost by paying attention to the merits of the authentication technology using both the “common key encryption method” and the “public key encryption method”. It is an object of the present invention to provide an authentication method and system that do not cost.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention achieves the N pieces of first key data K1, K2,..., KN (N is an integer of 1 or more) and a portion of the N pieces of first pieces. Identification including N pieces of second data KID1, KID2,..., KIDN for identifying each of the key data, and n pieces (n is an integer of 1 to N) of the N pieces of second data. First data storage means for storing a third data list having a plurality of data sets and fourth data for verifying the validity of the first key data set corresponding to the identification data set. And an authentication device comprising a computer device that performs authentication processing of authentication object data stored in the user device, and n fifth key data shared with the authentication device corresponding to the set of identification data Ki1, Ki2, ..., Kin and those of the n number of fifth key data N identification data KIDi1, KIDi2,..., KIDin for identifying each of them, sixth data for certifying the validity of the set of the fifth key data, and the authentication target In an authentication system comprising a second data storage means for storing eighth data, which is data, and a user device comprising a computer device capable of communicating with the authentication device, the authentication device includes the user device. When authenticating data to be authenticated, the authentication device comprises predetermined data Challenge Is transmitted to the user device, and the user device that has received the challenge receives the ninth data and the ninth data including the sixth data, the seventh data, the eighth data, and the received challenge. , Kin, the first key data consisting of one or more pieces of encrypted data obtained by performing a common key encryption process using one or more key data of the n pieces of fifth key data Ki1, Ki2,. The eleventh data that is a set of ten data and the twelfth data indicating the procedure of the common key encryption process are transmitted to the authentication device, and the authentication device that has received the plurality of data receives the received sixth data It is determined whether or not data is included in the set of identification data in the third data list, and the validity of the sixth data is verified. The validity of the received seventh data is determined as the fourth data. Using and verifying, Based on the received twelfth data, it is determined whether the received eleventh data is valid, the received sixth data is valid, and the received seventh data is valid. And an authentication method for authenticating that the eighth data included in the received eleventh data is valid when the received eleventh data is valid.
[0014]
According to the authentication method of the present invention, when authenticating whether or not the eighth data, which is authentication target data held by the user device, is valid by the authentication device, as shown in FIG. The challenge is generated at (SA1), and the challenge is transmitted to the user device (SA2).
[0015]
The user device that has received this challenge generates the tenth data (SA3) and the eleventh data and the twelfth data (SA4), and the sixth data, the seventh data, and the eleventh data. The twelfth data is transmitted to the authentication device (SA5).
[0016]
The eleventh data includes the ninth data and the tenth data, and the ninth data includes the eighth data and the received challenge.
[0017]
The tenth data is obtained by subjecting the ninth data to a common key encryption process using one or more key data of the n pieces of fifth key data Ki1, Ki2,..., Kin. It consists of one or more encrypted data.
[0018]
The twelfth data is data indicating a common key encryption processing procedure when the tenth data is generated.
[0019]
After that, the authentication device that has received the plurality of data determines whether the received sixth data is included in the set of identification data in the third data list, thereby determining the validity of the sixth data. (SA6) and the validity of the received seventh data is verified using the fourth data (SA7).
[0020]
This is because n pieces of fifth key data held by the user device are always stored in the first data storage means of the authentication device. The third data list includes a set of valid key identification data or a set of invalid key identification data. For example, if the set of identification data of the key included in the third data list is valid, the identification data matching the sixth data including the identification data of the n fifth key data is set. When the set is included in the third data list, it is determined that the received sixth data is valid. In addition, if the set of identification data of the key included in the third data list is invalid, when the set of identification data matching the sixth data is included in the third data, The received sixth data is determined to be invalid.
[0021]
Further, the fourth data for verifying the validity of the seventh data is always stored in the first data storage means of the authentication device. Here, the seventh data is, for example, a certificate that a third party proves by using a secret key that the set of the n fifth key data is a valid set, and the fourth data is the A public key corresponding to a secret key. The fourth data may be the same data as the seventh data.
[0022]
Further, the authentication device determines whether or not the received eleventh data is valid based on the received twelfth data (SA8).
[0023]
At this time, the authentication device generates thirteenth data including the eighth data included in the received eleventh data and the transmitted challenge, and uses the first key data based on the received twelfth data. Whether to determine that the received eleventh data is valid when the encrypted data obtained by subjecting the thirteenth data to encryption processing matches the tenth data included in the received eleventh data Alternatively, the tenth data included in the received eleventh data is decrypted using the first key data based on the received twelfth data, and the received fourteenth data. When the ninth data included in the data matches, it is determined that the received eleventh data is valid.
[0024]
Next, based on the results of these determinations, the authentication device includes the received sixth data as a set of identification data in the third data list, and the received seventh data is valid. When the received eleventh data is valid, the eighth data included in the received eleventh data is authenticated.
[0025]
Therefore, according to the present invention, when the authentication device authenticates the data, the user device does not need to generate a signature as in the conventional example, and therefore does not perform verification with a high processing cost. It becomes possible. Furthermore, since a common key cryptosystem is used, a plurality of keys are used, and a certificate exists for the key set, even if the key is stolen, it cannot be easily “spoofed”. In addition, the key management cost can be significantly reduced as compared with the case where “key: user = 1: 1” using the common key cryptosystem.
[0026]
Further, the present invention provides an authentication system capable of performing the above-described authentication method, wherein communication is performed between a user device comprising a computer device having means for storing data to be authenticated and the user device. In an authentication system including a computer device for authenticating data to be authenticated to an authentication device, the authentication device includes a first communication means for communicating with the user device, and a part of the user. N first key data K1, K2,... KN (N is an integer of 1 or more) shared with the apparatus, and N second data KID1, N for identifying each of the N first key data, KID2,..., KIDN, a third data list having a plurality of sets of identification data composed of n pieces (n is an integer not less than 1 and not more than N) of the N pieces of second data, and the identification data The first key data corresponding to the pair A fourth data for verifying the set of validity and the first data storage means for storing, comprising a predetermined data Challenge Means for transmitting to the user apparatus using the first communication means, and encryption processing means for encrypting arbitrary data using the first key data using a common key encryption method or encrypted data. First common key encryption processing means having at least one of decryption processing means for decrypting using key data, and from the user device, sixth data, seventh data, eleventh data, and twelfth data. Receiving means using the first communication means, ID verification means for determining whether the received sixth data is included in the set of identification data in the third data list, and the received Based on the received twelfth data, the verification means for verifying the validity of the seventh data using the fourth data, and whether the received eleventh data using the common key encryption processing means is valid Whether or not And the received sixth data is included as a set of identification data in the third data list, the received seventh data is valid, and the received eleventh data Authentication means for authenticating that the eighth data included in the received eleventh data is valid, and the user device is configured to communicate with the authentication device. Identifies each of the n fifth key data Ki, Ki2,..., Kin shared by the authentication apparatus corresponding to the set of identification data and the second communication means. .., KIDin as one set, the seventh data certifying the validity of the set of the fifth key data, and the authentication target data. Store the eighth data 2 data storage means and encryption processing means for encrypting arbitrary data using the fifth key data using a common key encryption method or decryption processing means for decrypting encrypted data using the fifth key data A ninth common key including at least a second common key cryptographic processing unit having the cryptographic processing unit, a unit for receiving the challenge from the authentication device by using the second communication unit, the eighth data, and the received challenge. Obtained by subjecting the data to a common key encryption process by the second common key encryption means using one or more key data of the n pieces of fifth key data Ki1, Ki2,..., Kin. Tenth data generating means for generating tenth data composed of one or more encrypted data, and twelfth data for generating a twelfth data indicating a common key encryption processing procedure in the generation of the tenth data. Using the second communication means, the data generation means, the sixth data, the seventh data, the eleventh data, the ninth data, and the tenth data are combined into the twelfth data. And an authentication system including means for transmitting to the authentication device, and the authentication device and the user device.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0028]
The authentication system to which the present invention is applied is composed of at least two devices of “authentication device” and “user device”, and can communicate between the “authentication device” and the “user device” when performing authentication. It must be in a state. For example, the “authentication device” and the “user device” are connected via a communication network such as the Internet or a local area network, a communication line such as a telephone line network, etc. There must be.
[0029]
The “user device” may be a device including a computer device capable of recording information. For example, a notebook or handheld personal computer, a well-known mobile phone, IC card, PDA (Personal Digital Assistance) Etc. can be used.
[0030]
In this authentication system, encrypted data obtained by encrypting data to be authenticated by a common key encryption method using a plurality of keys stored in the “user device”, key information of those keys, and the key information The certificate is presented to the “authentication apparatus”, and the authentication process is performed by verifying the data contents, the validity of the key information, and the certificate of the key information by the “authentication apparatus”. Details will be described below.
[0031]
FIG. 2 is a diagram illustrating a functional configuration of the authentication device according to the first embodiment of the present invention, and FIG. 3 is a diagram illustrating a functional configuration of the user device according to the first embodiment.
[0032]
In FIG. 2, reference numeral 1 denotes an authentication device, which comprises a known computer device connected to a communication network, and includes input / output means (communication means) 11, data storage means 12, ID verification means 13, and common key encryption processing means 14. , Verification means 15, challenge generation means 16, and encryption verification means 17. Each of these components is constituted by both hardware and software (computer program) in the computer apparatus.
[0033]
The input / output unit 11 has a data communication function with an external device, and outputs arbitrary data from the authentication device 1 to the external device, and inputs arbitrary data from the external device into the authentication device 1.
[0034]
The data storage means 12 has an information recording medium such as a known magnetic disk device or optical disk device, and N (N is an integer of 1 or more) common key encryption key data that is partially shared with the user device. , KN (key set K: = {Ki}, (1 <= i <= N)) 121 and identification data for identifying these common keys Ki A set of common key IDs (hereinafter referred to as KID_set) 122 composed of a certain key IDi (hereinafter referred to as KIDi), and a KID list (hereinafter referred to as KID_invalid_list) having a plurality of subsets of the common key ID set KID_set as elements. And a TTP public key Pk_TTP (124) corresponding to a secret key used when encrypting a certificate License_ij (i, j is an integer of 1 or more), which will be described later, by a public key cryptosystem. ing. This certificate License_ij is created by a digital signature using a trusted third party private key paired with the public key Pk_TTP.
[0035]
The common key Ki (121) corresponds to the first key data in the present invention, the KIDi (122) corresponds to the second data in the present invention, and the KID_invalid_list (123) in the third data list in the present invention. It corresponds to. The public key Pk_TTP (124) corresponds to the fourth data in the present invention.
[0036]
In the present embodiment, the KID set included in the KID_invalid_list is a KID set that cannot be used such as an unused KID set or a stolen KID set.
[0037]
The ID verification means 13 determines whether or not an arbitrary KID set (element of KID_set) is usable, that is, whether or not it is an element of the set KID_invalid_list, and verifies the validity of the arbitrary KID set. .
[0038]
The common key encryption processing means 14 has a function of encrypting arbitrary data using any of the common keys Ki and a function of combining encrypted data encrypted using any of the common keys Ki. .
[0039]
The verification unit 15 stores in the data storage unit 12 the validity of the certificate License_ [i1, i2,..., In] by a trusted third party for an arbitrary set of KIDs (i1, i2,..., In). And a function to verify using the public key Pk_TTP.
[0040]
The challenge generation means 16 has a function of generating a challenge made of random data such as random numbers or randomly extracted character data, or fixed data set in advance.
[0041]
The cryptographic verification unit 17 has a function of verifying the validity of the encrypted data signed by the message authentication code generated with the arbitrary common key Ki, and further confirms the validity of the encrypted data with the verification result, the ID verification unit 13 and the verification. Based on the verification result of the means 15, it has a function of verifying the validity of the electronic value data Value to be authenticated. Details of this verification function will be described later.
[0042]
As shown in FIG. 3, the user device 2 comprises a known computer device connected to a communication network, and includes an input / output means (communication means) 21, a data storage means 22, a common key encryption processing means 23, an electronic device. The value management means 24 and the communication data processing means 25 are comprised. Each of these components is constituted by both hardware and software (computer program) in the computer apparatus.
[0043]
The input / output means 21 outputs arbitrary data from the user device 2 to the external device, and inputs arbitrary data from the external device into the user device 2.
[0044]
The data storage means 22 includes n keys Ki1, Ki2 arbitrarily selected from the set K of keys held by the authentication device 1 (where n is an integer between 1 and N and sufficiently smaller than N). , ..., Kin, a set of KIDs corresponding to these keys (i1, i2, ..., in), and a certificate License_ [i1, i2, ..., in] and electronic value data Value to be authenticated in this authentication system.
[0045]
The KID set (i1, i2,..., In) is included in the KID_invalid_list as a plurality of subsets in the common key ID set KID_set in the authentication device 1. Further, only one user device 2 stores combinations of individual keys included in KID_invalid_list.
[0046]
The n keys Ki1, Ki2,..., Kin correspond to the fifth key data in the present invention, and the KID set (i1, i2,..., In) corresponds to the sixth data in the present invention. The certificate License_ [i1, i2,..., In] corresponds to the seventh data of the present invention, and the electronic value data Value corresponds to the eighth data of the present invention.
[0047]
Here, the electronic value data Value means stock certificates, horse betting tickets, lotteries, bills of lading, banknotes and coins, gift certificates, gift certificates, large discount coupons, product vouchers, tickets, regular tickets, movie advance tickets, theme parks Digital data that has some value, including digital data such as admission tickets, event tickets, identification cards, employee ID cards, etc. Accordingly, authentication such as value authentication, individual authentication, and attribute authentication can be performed according to the contents of the electronic value data Value.
[0048]
The common key encryption processing means 23 has a function of generating encrypted data MAC obtained by encrypting an arbitrary message with an arbitrary key Kij.
[0049]
“DES” is known as an example of a typical encryption function in the common key cryptosystem. “DES” is described in, for example, “National Institute of Standards and Technology (NIST), FIPS Publication 46-3: Data Encryption Standard (DES), 1999”.
[0050]
The electronic value management means 24 has a function of managing electronic value data Value to be authenticated by this system. Here, “management” newly stores the electronic value data Value in the data storage means 22 from the external apparatus provided with the authentication apparatus 1 or from the external apparatus provided with the authentication apparatus 1 via the input / output means 21. And updating the electronic value data Value stored in the data storage means 22 in accordance with this instruction. It goes without saying that this processing differs depending on the type of electronic value data Value as described above.
[0051]
Note that the number n of keys Ki1, Ki2,..., Kin and KID held by the user device 2 is fixed in all the user devices 2 when there are a plurality of user devices 2, or each usage. It may be different for each person device 2.
[0052]
The communication data processing unit 25 receives a challenge from the authentication device 1 via the input / output unit 21, acquires data to be transmitted to the authentication device 1 from the data storage unit 22, and stores the electronic value data Value. Data including processing to be described later is generated for the predetermined data included, and these data are transmitted to the authentication device 1 via the input / output means 21.
[0053]
Next, the operation of the authentication system having the above configuration will be described with reference to FIG.
[0054]
In a state where the user device 2 is connected to the authentication device 1 so as to be communicable, the authentication device 1 generates a challenge r by the challenge generation unit 16 (SB1), and uses the input / output unit 11 to the user device 2 (SB2).
[0055]
The user device 2 that has received the challenge r from the authentication device 1 acquires the electronic value data Value from the data storage unit 22 by the communication data processing unit 25, and the data DATA that connects the electronic value data Value and the received challenge r. (= Value + r) (9th data) is generated (SB3) and the data DATA is encrypted using one or more of the keys Kij (1 <= j <= n) stored in the data storage means 22 One encryption data MAC (tenth data) or individual encryption data MAC_ij is generated for each key Kij used for encryption, and procedure data Dstep for encryption processing is generated (SB4).
[0056]
At this time, the communication data processing means 25 can use one of the following three methods (a), (b), and (c) when encrypting the data DATA.
[0057]
(a) One encrypted data MAC obtained by encrypting the data DATA is generated by using one key Kij selected for use in encryption processing.
[0058]
(b) Generate encrypted data obtained by encrypting data DATA using one of a plurality of keys Kij selected for use in encryption processing, and further encrypt the encrypted data using another key Kij. By repeating this, one encrypted data MAC is generated. The number of repetitions of the encryption process at this time is the number of the selected keys Kij.
[0059]
(c) Data DATA is encrypted using each of the plurality of keys Kij selected for use in the encryption process, and individual encrypted data MAC_ij (1 <= j <= n) is generated for each key Kij.
[0060]
Further, the communication data processing means 25 generates, as procedure data Dstep (twelfth data), data representing the order using KIDij and identification data of the key Kij used for the encryption processing and the key Kij.
[0061]
Next, the communication data processing means 25 uses the KID set (i1, i2,..., In), the certificate License_ [i1, i2,..., In] for the KID set, the data DATA, and the generated encrypted data. The group “DATA + MAC” (11th data) or “DATA + MAC_i1 +... + MAC_in” and the procedure data Dstep are transmitted to the authentication device 1 via the input / output means 21 (SB5 to SB8).
[0062]
Upon receiving these data, the authentication device 1 receives the received KID set (i1, i2,..., In), “DATA + MAC” or “DATA + MAC_1 +... + MAC_n”, and the certificate License_ [i1, i2 ,..., In] using the ID verification unit 13, whether the KID set (i1, i2,..., In) matches the KID set included in the KID_invalid_list stored in the data storage unit 12. The validity of the key pair is verified by checking whether or not (SB9). As a result of the verification, when it is determined that the key pair is invalid, the processing is terminated.
[0063]
If the key combination is valid as a result of the verification, the verification means 15 is used to verify the certificate License_ [i1, i2,..., In] with the TTP public key Pk_TTP stored in the data storage means 12. Verification is performed (SB10). As a result of this verification, if the certificate License_ [i1, i2,..., In] is not valid, the process is terminated.
[0064]
As a result of the above verification, if the certificate License_ [i1, i2,..., In] is valid, the encrypted data “MAC” or “MAC_i1 +. Verify whether + MAC_in is correct.
[0065]
At this time, the cryptographic verification means 17 can use one of the following two methods (a) and (b) when verifying the cryptographic data.
[0066]
(a) Using the electronic value data Value (eighth data) included in the received data and the transmitted challenge r, data DATA ′ (13th data) is generated by connecting them. Further, a key Kij based on the received procedure data Dstep (twelfth data) is extracted from the data storage means 12, and the generated data DATA 'is encrypted by the common encryption processing means 17 using this key Kij, and thus obtained. When the received encrypted data matches the received encrypted data MAC or MAC_ij, it is determined that the received encrypted data MAC or MAC_ij (tenth data) is valid.
[0067]
(b) A key Kij based on the received procedure data Dstep (12th data) is extracted from the data storage means 12, and the received encryption data MAC or MAC_ij (10th data) is extracted by the common encryption processing means 17 using this key Kij. ), And when the data (14th data) obtained by the decryption matches the received data DATA, the received encrypted data “MAC” or “DATA + MAC_1 +... + MAC_n” (first 11 data) is valid.
[0068]
As a result of the verification, when it is determined that the encrypted data “MAC” or “MAC_i1 +... + MAC_in” is correct, the electronic value data Value included in the received data DATA (= Value + r) is assumed to be valid data. Authentication is performed (SB12).
[0069]
In the above verification, the authentication process is normally completed only when it is found that “KID set is valid”, “certificate verification is accepted”, and “encryption verification is accepted”. In other cases, the authentication device 1 determines that the “KID set is invalid”, “KID set is forged”, or “DATA has been tampered with” and authenticates. Do not do.
[0070]
If the authentication method and the authentication system in the above-described embodiment are used, the authentication process can be performed at high speed if the authentication side hardware has high performance, and the key management cost can be reduced as compared with the conventional method. Is possible.
[0071]
For example, if there is a user device owned by 100 million users in an authentication system using the “common key cryptosystem”, the “common key cryptosystem” is used, so high-speed authentication processing is possible. On the other hand, 100 million keys must be managed on the authentication device side. In a system in which a large number of authentication devices exist, key management cost is incurred only by key distribution.
[0072]
On the other hand, in the above embodiment, even if there are 100 million user devices as described above, it is only necessary to manage about 1000 keys. Further, since the “common key cryptosystem” is used, high-speed authentication processing can be realized. For example, if three keys are assigned to each user device out of 1,000 keys, a key can be uniquely assigned to 166 million user devices.
[0073]
In addition, when a key is stolen by about 30 user devices, that is, when about 100 keys are stolen by a malicious third party, the malicious third party selects an appropriate one from the 100 stolen keys. It is possible to attempt authentication using a key of various combinations (possible combinations are 161,700 pairs).
[0074]
However, when using the method and apparatus of the present embodiment, a malicious third party can rely on a trusted third party certificate for a properly combined key, except for a stolen user device key combination. Can not have. Therefore, a malicious third party cannot authenticate even if a key combination other than the key combination of the stolen user device is used. Further, since the authentication device 1 is provided with a KID invalid list relating to the key combination of the stolen user device and the key combination that is not used, the invalidation check is performed, so that even if the key combination is used, authentication is not performed. .
[0075]
Note that the number n of keys Kij held by the user apparatus 2 is changed according to the value of the electronic value data Value so that the higher the value of the electronic value data Value, the more difficult it becomes to decrypt the encrypted data. May be.
[0076]
Certificate License_ [i1, i2,..., In] is stored in the first data storage means 12, and the verification means 15 receives the certificate License_ [i1, i2, ..., in] received from the user apparatus 2. The certificate License_ [i1, i2,..., In] stored in the data storage unit 12 may be compared to verify the validity of the received certificate License_ [i1, i2,. .
[0077]
In the present embodiment, the KID_invalid_list held by the authentication device 1 describes a set of invalid key identification data. Instead, a list KID_valid_list describing a set of valid key identification data is used. Thus, the validity of the set of KIDs (i1, i2,..., In) received from the user device 2 may be verified.
[0078]
Moreover, it is only necessary that communication between the authentication device 1 and the user device 2 is possible when performing authentication, and the connection between the authentication device 1 and the user device 2 may be directly connected. Needless to say, it may be a connection via a communication network such as the Internet or a telephone line, or a communication using electromagnetic waves, ultrasonic waves or infrared rays.
[0079]
Next, a second embodiment of the present invention will be described.
[0080]
FIG. 5 is an overall configuration diagram of an authentication system according to the second embodiment. The authentication system of the second embodiment has a configuration in which a remote data management device 3 is provided in addition to the authentication device 1 and the user device 2 of the first embodiment.
[0081]
FIG. 6 is a diagram showing a functional configuration of the remote data management device 3. In the figure, the remote data management device 3 includes an input / output means 31 and a data storage means 32.
[0082]
The input / output unit 31 has a function of outputting arbitrary data to the external device, receiving arbitrary data from the external device, and storing the data in the data storage unit 32.
[0083]
The data storage means 32 is a common key K1, K2,..., KN (key set K: = {Ki}, (1 <= i) which is key data of N common key cryptosystems used in this authentication system. <= N)) 131, a common key ID set data (KID_set) 132 composed of key IDi (KIDi) as identification data for identifying these common keys Ki, and a common key ID set KID_set Release of TTP corresponding to private key used when encrypting KID list (KID_invalid_list) 133 having multiple subset elements and certificate License_ij (i and j are integers of 1 or more) by public key cryptography Of the key Pk_TTP (134), at least data that is not stored in the data storage unit 12 of the authentication device 1 is held.
[0084]
That is, the remote data management device 3 holds a part or all of the data stored in the data storage means 12 of the authentication device 1 in the first embodiment described above, and in the second embodiment. The data storage means 12 of the authentication device 1 stores at least data that is not held by the remote data management device 3.
[0085]
Further, the authentication device 1 can acquire data necessary for performing authentication processing from the remote data management device 3 via the input / output means 11.
[0086]
Therefore, in the second embodiment, authentication processing can be performed without having the authentication device 1 hold all important data. Thereby, when a plurality of authentication devices 1 are provided, it becomes easy to always use the same data in the plurality of authentication devices 1.
[0087]
【The invention's effect】
As described above, according to the present invention, when the authentication device authenticates the data, the user device does not need to generate a signature as in the conventional example, and thus it is not necessary to perform verification with a high processing cost. Fast authentication processing is possible. Furthermore, since a common key cryptosystem and a plurality of keys are used and a certificate for a key set exists, even if a third party steals the key, it cannot be easily “spoofed”. In addition, since the number of keys can be greatly reduced compared to the case where one key is assigned to one user using a common key cryptosystem as in the conventional example, the key management cost is greatly increased. It is very effective that it can be reduced to a very low level.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating an authentication method according to the present invention.
FIG. 2 is a functional configuration diagram of an authentication apparatus according to the first embodiment of the present invention.
FIG. 3 is a functional configuration diagram of a user device according to the first embodiment of the present invention.
FIG. 4 is a flowchart illustrating authentication processing according to the first embodiment of the present invention.
FIG. 5 is a block diagram showing an authentication system in a second embodiment of the present invention.
FIG. 6 is a functional configuration diagram of a remote data management device according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Authentication apparatus, 2 ... User apparatus, 3 ... Remote data management apparatus, 11 ... Input-output means (1st communication means), 12 ... Data storage means (1st data storage means), 13 ... ID verification means, 14 ... common key encryption processing means (first common key encryption processing means), 15 ... verification means, 16 ... challenge generation means, 17 ... encryption verification means (encryption verification means and authentication means), 21 ... input / output means (second communication) Means), 22 ... data storage means (second data storage means), 23 ... common key encryption processing means (second common key encryption processing means), 24 ... electronic value management means, 25 ... communication data processing means (table 10, 12 data generating means), 31... Input / output means (third communication means), 32... Data storage means (third data storage means).

Claims (18)

N pieces of first key data K 1, K 2,..., K N (N is an integer equal to or greater than 1) that share a part with the user apparatus and N pieces of N pieces of key data for identifying each of the N pieces of first key data. A third data list having a plurality of sets of identification data composed of second data KID1, KID2,..., KIDN, and n (n is an integer of 1 to N) of the N second data. And a first data storage means for storing the fourth data for verifying the validity of the first key data set corresponding to the identification data set and stored in the user device. An authentication device comprising a computer device that performs authentication processing of data to be authenticated;
N pieces of fifth key data Ki1, Ki2,..., Kin shared with the authentication apparatus corresponding to the set of identification data and n pieces of identification for identifying each of the n pieces of fifth key data. Stores sixth data having data KIDi1, KIDi2,..., KIDin as one set, seventh data certifying the validity of the set of the fifth key data, and eighth data as the authentication target data. An authentication method for the authentication object data in an authentication system comprising a user device comprising a computer device comprising a second data storage means and capable of communicating with the authentication device,
The authentication device transmits a challenge consisting of predetermined data to the user device,
The user device that has received the challenge has the sixth data and the seventh data,
Ninth data composed of the eighth data and the received challenge, and one or more key data of the n fifth key data Ki1, Ki2,. Sends eleventh data, which is a set of tenth data composed of one or more encrypted data obtained by performing the common key encryption process, and twelfth data indicating the procedure of the common key encryption process to the authentication device And
In the authentication device that has received the sixth data, the seventh data, the eleventh data, and the twelfth data, is the received sixth data included in the set of identification data in the third data list? And verifying the validity of the sixth data by determining whether or not
Validating the received seventh data using the fourth data,
Furthermore, based on the received twelfth data, it is determined whether the received eleventh data is valid,
When the received sixth data is valid, the received seventh data is valid, and the received eleventh data is valid, it is included in the received eleventh data. And authenticating that the eighth data is valid. When the user device generates the tenth data, the fifth key data, which is different for each encryption process, is used, and the ninth data is encrypted using predetermined fifth key data. Furthermore, one encryption data obtained by performing one or more encryption processes using other different fifth key data is used as the tenth data, and the identification data of the fifth key data used for the encryption process The authentication method according to claim 1, wherein information indicating the order is the twelfth data. When the user device generates the tenth data, the fifth device uses different fifth key data for each encryption processing, and the ninth device performs encryption processing using two or more different fifth key data. Two or more pieces of encrypted data obtained corresponding to the number of the fifth key data used for the encryption process are connected to form the tenth data, and information indicating the order of connection of the encrypted data; 2. The authentication method according to claim 1, wherein identification data of the fifth key data used for encryption processing of each encrypted data is the twelfth data. When the authentication device determines whether the received eleventh data is valid, the authentication device generates thirteenth data including the eighth data included in the received eleventh data and the transmitted challenge. And the encrypted data obtained by subjecting the thirteenth data to cryptographic processing using the first key data based on the received twelfth data matches the tenth data included in the received eleventh data. 2. The authentication method according to claim 1, wherein the received eleventh data is determined to be valid. The authentication device includes the 14th data obtained by decrypting the 10th data included in the received 11th data using the first key data based on the received 12th data, and the received The authentication method according to claim 1, wherein when the ninth data included in the eleventh data matches, the received eleventh data is determined to be valid. A user device comprising a computer device having means for storing data to be authenticated, and a computer device for authenticating the validity of the data to be authenticated by communicating with the user device; In the authentication system with
The authentication device
First communication means for communicating with the user device;
N pieces of first key data K 1, K 2,..., K N (N is an integer equal to or greater than 1) that share a part with the user apparatus and N pieces of N pieces of key data for identifying each of the N pieces of first key data. A third data list having a plurality of sets of identification data composed of second data KID1, KID2,..., KIDN, and n (n is an integer of 1 to N) of the N second data. First data storage means for storing fourth data for verifying the validity of the set of the first key data corresponding to the set of identification data;
Means for transmitting a challenge comprising predetermined data to the user device using the first communication means;
First having at least one of encryption processing means for encrypting arbitrary data using the first key data using a common key encryption method and decryption processing means for decrypting encrypted data using the first key data A common key encryption processing means;
Means for receiving, from the user device, sixth data, seventh data, eleventh data, and twelfth data using the first communication means;
ID verification means for determining whether the received sixth data is included in the set of identification data in the third data list and verifying the validity of the sixth data;
Verification means for verifying the validity of the received seventh data using the fourth data;
Based on the received twelfth data, cryptographic verification means for determining whether the received eleventh data is valid using the common key encryption processing means;
When the received sixth data is valid, the received seventh data is valid, and the received eleventh data is valid, it is included in the received eleventh data. Authentication means for authenticating that the eighth data is valid,
The user device is
A second communication means for communicating with the authentication device;
N pieces of fifth key data Ki1, Ki2,..., Kin shared with the authentication apparatus corresponding to the set of identification data and n pieces of identification for identifying each of the n pieces of fifth key data. The sixth data having data KIDi1, KIDi2,..., KIDin as one set, the seventh data certifying the validity of the fifth key data set, and the eighth data as the authentication target data, Second data storage means for storing
At least the encryption processing means of an encryption processing means for encrypting arbitrary data using the fifth key data or a decryption processing means for decrypting encrypted data using the fifth key data; Having a second common key encryption processing means;
Means for receiving the challenge from the authentication device using the second communication means;
The second common key using one or more key data of the n pieces of fifth key data Ki1, Ki2,..., Kin for the ninth data comprising the eighth data and the received challenge. Tenth data generating means for generating tenth data composed of one or more pieces of encrypted data obtained by performing the common key encryption processing by the encryption processing means;
A twelfth data generating means for generating the twelfth data indicating a procedure of a common key encryption process in the generation of the tenth data;
Using the second communication means, the sixth data, the seventh data, the ninth data, and the tenth data are combined with the eleventh data and the twelfth data to the authentication device. An authentication system comprising: means for transmitting. The tenth data generation means uses different fifth key data for each encryption process, encrypts the ninth data using predetermined fifth key data, and further uses another different fifth key data. Means for generating, as the tenth data, one piece of encrypted data obtained by performing one or more encryption processes using
7. The twelfth data generation means includes means for generating data including identification data of the fifth key data used for the encryption processing and information indicating an order as the twelfth data. The authentication system described in. The tenth data generation means uses different fifth key data for each encryption process, encrypts the ninth data using two or more different fifth key data, and uses the fifth key data used for the encryption process. Means for generating, as the tenth data, data obtained by concatenating two or more pieces of encrypted data obtained corresponding to the number of five key data;
The twelfth data generation means generates data including information indicating the order of connection of the encrypted data and identification data of the fifth key data used for encryption processing of each encrypted data as the twelfth data. The authentication system according to claim 6, further comprising: The encryption verification unit generates thirteenth data including the eighth data included in the received eleventh data and the transmitted challenge, and uses the first key data based on the received twelfth data. Means for judging that the received eleventh data is valid when the encrypted data obtained by subjecting the thirteenth data to cryptographic processing and the tenth data included in the received eleventh data match. Or the fourteenth data obtained by decrypting the tenth data included in the received eleventh data using the first key data based on the received twelfth data, and the received first data When there is a match with the ninth data included in the eleventh data, it has any one of means for judging that the received eleventh data is valid Authentication system according to Motomeko 6. The authentication device comprises means for transmitting update instruction information for the eighth data to the user device using the first communication means,
The user device receives the update instruction information from the authentication device using the second communication means, and the second data storage means stores the update instruction information based on the received update instruction information. The authentication system according to claim 6, further comprising: 8 means for updating data. The number n of the fifth key data stored in the second data storage means of the user device is set to a number corresponding to the value of the eighth data. 6. The authentication system according to 6. A plurality of the user devices, each user device storing the plurality of different fifth key data, the sixth data, and the seventh data in the second data storage means;
The first data storage means of the authentication device stores first key data including all the fifth key data possessed by the plurality of user devices, and the seventh data possessed by each user device. The authentication system according to claim 6, wherein the fourth data for verifying the validity is stored. A third data storage means for storing at least part of the N pieces of first key data, the N pieces of second data, the third data list, and the fourth data; Providing a remote data management device comprising a third communication means for communicating with the authentication device;
The first communication means of the authentication device has a communication means with the remote data management device,
The first data storage means of the authentication device stores at least the third data of the N first key data, the N second data, the third data list, and the fourth data. Stores data not stored in the means,
7. The authentication system according to claim 6, wherein the authentication device comprises means for referring to data stored in third data storage means of the remote data management device using the first communication means. . A user device comprising a computer device having means for storing data to be authenticated, and a computer device for authenticating the validity of the data to be authenticated by communicating with the user device; In the authentication apparatus in the authentication system comprising:
A communication means for communicating with the user device;
N pieces of first key data K 1, K 2,..., K N (N is an integer equal to or greater than 1) that share a part with the user apparatus and N pieces of N pieces of key data for identifying each of the N pieces of first key data. A third data list having a plurality of sets of identification data composed of second data KID1, KID2,..., KIDN, and n (n is an integer of 1 to N) of the N second data. Data storage means for storing fourth data for verifying the validity of the set of the first key data corresponding to the set of identification data;
Means for transmitting a challenge comprising predetermined data to the user device using the communication means;
A common key having at least one of encryption processing means for encrypting arbitrary data using the first key data using a common key encryption method and decryption processing means for decrypting encrypted data using the first key data Cryptographic processing means;
From the user apparatus, n pieces of identification data KIDi1, KIDi2,..., KIDin for identifying each of the n pieces of fifth key data Ki1, Ki2,. A sixth data that is a set, a seventh data that proves the validity of the set of the fifth key data, an eighth data that is authentication target data, a ninth data that consists of the challenge, and the ninth data 10th data composed of one or more pieces of encrypted data obtained by performing a common key encryption process using one or more pieces of key data among the n pieces of fifth key data Ki1, Ki2,. Means for receiving, using the communication means, eleventh data having a set of twelfth data and twelfth data indicating a procedure of common key encryption processing in generation of the tenth data
ID verification means for determining whether the received sixth data is included in the set of identification data in the third data list and verifying the validity of the sixth data;
Verification means for verifying the validity of the received seventh data using the fourth data;
Based on the received twelfth data, cryptographic verification means for determining whether the received eleventh data is valid using the common key encryption processing means;
When the received sixth data is valid, the received seventh data is valid, and the received eleventh data is valid, it is included in the received eleventh data. An authentication device for authenticating that the eighth data is valid. The encryption verification unit generates thirteenth data including the eighth data included in the received eleventh data and the transmitted challenge, and uses the first key data based on the received twelfth data. Means for judging that the received eleventh data is valid when the encrypted data obtained by subjecting the thirteenth data to cryptographic processing and the tenth data included in the received eleventh data match. Or the fourteenth data obtained by decrypting the tenth data included in the received eleventh data using the first key data based on the received twelfth data, and the received first data When there is a match with the ninth data included in the eleventh data, it has any one of means for judging that the received eleventh data is valid Authentication device according to Motomeko 14. A user device comprising a computer device having means for storing data to be authenticated, and a computer device for authenticating the validity of the data to be authenticated by communicating with the user device; In the user device of the authentication system comprising:
A communication means for communicating with the authentication device;
N pieces of fifth key data Ki1, Ki2,..., Kin that are shared with the authentication device corresponding to a set of identification data, and n pieces of identification data for identifying each of the n pieces of fifth key data. Stores sixth data that includes KIDi1, KIDi2,..., KIDin as one set, seventh data that proves the validity of the fifth key data set, and eighth data that is the authentication target data. Data storage means,
At least the encryption processing means of an encryption processing means for encrypting arbitrary data using the fifth key data or a decryption processing means for decrypting encrypted data using the fifth key data; Having a common key encryption processing means;
Means for receiving a challenge comprising predetermined data from the authentication device using the communication means;
The second common key using one or more key data of the n pieces of fifth key data Ki1, Ki2,..., Kin for the ninth data comprising the eighth data and the received challenge. Tenth data generating means for generating tenth data composed of one or more pieces of encrypted data obtained by performing the common key encryption processing by the encryption processing means;
A twelfth data generating means for generating the twelfth data indicating a procedure of a common key encryption process in the generation of the tenth data;
Sending the sixth data, the seventh data, the eleventh data, and the twelfth data to the authentication device using the communication means. And a user device for an authentication system. The tenth data generation means uses different fifth key data for each encryption process, encrypts the ninth data using predetermined fifth key data, and further uses another different fifth key data. Means for generating, as the tenth data, one piece of encrypted data obtained by performing one or more encryption processes using
The twelfth data generation means includes means for generating data including identification data of the fifth key data used for the encryption processing and information indicating the order as the twelfth data. A user device of the authentication system described in 1. The tenth data generation means uses different fifth key data for each encryption process, encrypts the ninth data using two or more different fifth key data, and uses the fifth key data used for the encryption process. Means for generating, as the tenth data, data obtained by concatenating two or more pieces of encrypted data obtained corresponding to the number of five key data;
The twelfth data generation means generates data including information indicating the order of connection of the encrypted data and identification data of the fifth key data used for encryption processing of each encrypted data as the twelfth data. The user apparatus of the authentication system according to claim 16, comprising:

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