JP2002232410A - Equipment and method for communicating ciphered data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the communication equipment/method of ciphered data, which can accurately prevent a person operating communication equipment from taking out communication data in communication equipment as it is. SOLUTION: In the first operation means 11 and the second operation means 21 of first communication equipment 1 and second communication equipment 2, which are mutually connected through a network 3, the password key of a common system is generated as a session key. Data transmitted/received with opposite communication equipment through the network 3 are ciphered by the session key, to be transmitted through the network. The first and second operation means are constituted of outer access inhibiting devices inhibiting the access of data from outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to encrypted data transmitted and received between a first communication device and a second communication device via a network in order to protect the data from being transmitted to a third party. More specifically, the present invention relates to a communication device and method, specifically, a distributed communication system having a specific number of recipients, and a first or second communication system in which a data transmission path passes through an insecure path such as the Internet. The present invention relates to a communication apparatus and method for encrypted data which is effective when applied to a system in which the management of the apparatus itself is not 100% reliable.
In particular, the present invention is applied to a case where a membership system provided by a server connected to the Internet is used from a plurality of member clients, or an unspecified number of users are set up in a public place by setting up clients. TECHNICAL FIELD The present invention relates to a communication device and a communication method for encrypted data that are effective in a case where the communication method is used.

[0002]

2. Description of the Related Art As a secure data transmission method effective for a communication device of this type of encrypted data, for example, Nets in the United States
cape Communications' SSL (Secure Socket Laye
r), IFTF (Internet Engineering Task Force)
TLS (Tran) standardized as RFC2246 by
sfer Layer Security) is known.

In such a conventional technique, data on a communication path is encrypted with a session key so that a person who should not originally receive the communication data cannot retrieve the original communication data.

[0004]

However, in the above-mentioned prior art, a person who can operate a device used for communication and who should not originally receive communication data stores a session key during a session. There is a problem in that a session key is obtained by peeping into the stored memory, and the original communication data may be extracted from the session key and communication data encrypted with the session key.

Further, conventionally, since communication data is unprotected after being decoded by the communication device, there is a problem that a person who can operate the communication device can take out the decoded communication data as it is. is there.

[0006] The present invention has been made in view of the above,
An object of the present invention is to provide an encrypted data communication apparatus and method capable of appropriately preventing a person who can operate the communication apparatus from taking out communication data in the communication apparatus as it is.

[0007]

In order to achieve the above object, according to the present invention, data transmitted and received between a communication apparatus and a communication apparatus via a network is encrypted so as to protect the data from a third party. A communication device connected to a network for transmitting and receiving data to and from the network, and an arithmetic device connected to the communication device, the secret device comprising: A data holding unit for storing data including a key and a public key of a partner communication device; a random number generation unit for generating a random number; a cryptographic processing unit for performing encryption processing and decryption processing; And a first operation means including an encryption key generation means for generating an encryption key of a common key system from one or more numerical data by an algorithm. And gist to be configured as an external access prohibition device which can prevent access from the outside to the data.

According to the first aspect of the present invention, the communication device generates an encryption key of a common key system as a session key in the arithmetic means, and transmits data to be transmitted / received to / from the other communication device via the network. Since it is encrypted with the session key and transmitted through the communication means, and the arithmetic means is constituted by an external access prohibition device that can prohibit external data from being accessed externally, a person who can operate the communication device obtains the session key. Removal can be prevented.

Further, the present invention described in claim 2 is based on claim 1.
In the described invention, when the arithmetic means configured as the external access prohibiting device outputs the internal data to the outside, a digital watermark is inserted into the internal data or the internal data is converted into analog data and output. The gist of the present invention is to have a data processing unit that performs the processing.

According to the second aspect of the present invention, since the internal data of the arithmetic means is inserted with a digital watermark by the data processing means or converted into analog data and output, the data without the digital watermark is inserted. And digital data itself that is not analog data cannot be obtained.

Further, the present invention according to claim 3 provides the invention according to claim 1.
In the invention described above, the gist is that the external access prohibition device is configured by a tamper-resistant device.

According to the third aspect of the present invention, the external access prohibition device is a tamper-resistant device.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the operator obtains an ID of the operation means itself, and obtains a public key corresponding to the ID of the operation means. The gist of the present invention is to further include a corresponding public key acquisition unit.

According to the fourth aspect of the present invention, since the ID of the operation means is obtained and the public key corresponding to the ID of the operation means is obtained, even if there are a plurality of communication devices,
It is possible to accurately acquire the ID of the arithmetic unit of the communication device.

According to a fifth aspect of the present invention, there is provided a cipher for encrypting and transmitting data transmitted and received between a first communication device and a second communication device via a network so as to protect the data from a third party. A first communication unit connected to a network for transmitting data to the network or receiving data from the network; A first data holding means for storing data including a secret key of the first calculation means itself and a public key of the second communication device; A first random number generating means for generating one random number, a first encryption processing means for performing encryption processing and decryption processing, and a predetermined algorithm shared by the first and second arithmetic means.
First arithmetic means including first encryption key generation means for generating a common key encryption key as a session key from one or more numerical data, and the second communication device is connected to a network. A second communication means for transmitting data to the network or receiving data from the network, and a second arithmetic means connected to the second communication means, A second data holding unit for storing data including a secret key of the arithmetic unit itself and a public key of the first communication device; a second encryption processing unit for performing encryption processing and decryption processing; and generation of a second random number A second random number generating means for generating a common key cryptographic key as a session key from one or more numerical data by a predetermined algorithm shared by the first and second arithmetic means.
And second operation means containing encryption key generation means of
The first communication device generates a first random number by a first random number generation unit, stores the first random number in a first data holding unit, and stores the first random number in a first encryption processing unit. And encrypting the first random number by a public key method using the public key of the first communication means, transmitting the encrypted first random number from the first communication means to the second communication device via the network, The communication device receives the encrypted first random number transmitted from the first communication device by a second communication unit, and converts the received encrypted first random number into a second encryption device. Processing means for decrypting with its own secret key, second random number generating means for generating a second random number, storing the first and second random numbers in the second data holding means, and second cryptographic processing means First in
And a second random number are encrypted by a public key method using a public key of the first communication device, and the encrypted first and second random numbers are encrypted.
From the second communication means via the network to the first random number.
The first communication device receives the encrypted first and second random numbers transmitted from the second communication device by the first communication means, and receives the received first and second random numbers. The encrypted first and second random numbers are decrypted by the first encryption processing means using its own secret key, and it is verified that the decrypted first random number is equal to the stored first random number. The first encryption key generation means generates a common key encryption key as a session key by a predetermined algorithm using the first and second random numbers, and uses the generated common key encryption key to generate the first key. The second random number is encrypted by the first cryptographic processing means, and the encrypted second random number is transmitted from the first communication means to the second communication device via the network. The encrypted communication transmitted from the first communication device; The second random number received by the second communication means, and the second encryption key generation means uses the first and second random numbers stored in the second data holding means to generate the common key by the predetermined algorithm. A second encryption processing means generates an encryption key of the encryption method as a session key, and decrypts the received second random number with the generated encryption key of the common key method in the second encryption processing means. The gist is to verify that the random number is equal to the held second random number.

According to the fifth aspect of the present invention, the first and second communication devices generate an encryption key of a common key method as a session key in their respective arithmetic means, and communicate with the partner communication device via a network. The data transmitted and received between the devices is encrypted with the session key and transmitted via the communication means.

Further, according to the present invention, there is provided a cipher for encrypting and transmitting data transmitted and received between a first communication device and a second communication device via a network so as to protect the data from a third party. A first communication unit connected to a network for transmitting data to the network or receiving data from the network; A first data holding means for storing data including a secret key of the first calculation means itself and a public key of a second communication device; ID acquisition means for acquiring an ID of the first arithmetic means itself, first random number generation means for generating a first random number, first encryption processing means for performing encryption processing and decryption processing, and the first And second arithmetic means A first operation means including first encryption key generation means for generating a common key type encryption key as a session key from one or more numerical data by a shared predetermined algorithm, and A communication device connected to a network for transmitting data to the network or receiving data from the network; and a second operation device connected to the second communication device. Means for storing data including a secret key of the second operation means itself and a public key of the first communication device, a second encryption means for performing encryption processing and decryption processing. Processing means for generating a second random number;
And a second encryption key generation means for generating a common key encryption key as a session key from one or more numerical data by a predetermined algorithm shared by the first and second arithmetic means. The first communication device generates a first random number with a first random number generation unit, and stores the first random number in a first data holding unit; The ID of the first calculating means itself is acquired by the ID acquiring means, and the acquired ID and the first random number are obtained by the first acquiring means.
And encrypts the encrypted ID, the first random number, and the unencrypted ID from the first communication means to the network by using the public key of the second communication device in the encryption processing means. The second communication device transmits the encrypted ID, the first random number, and the unencrypted ID transmitted from the first communication device to the second communication device via a second communication device. Receiving the encrypted ID and the first random number with a secret key of the second communication device itself in a second encryption processing unit, and receiving the received unencrypted ID; And the decrypted I
D is compared to verify that they are equal, a second random number is generated by a second random number generating means, and the first and second random numbers are generated.
Is stored in the second data holding means, and the first and second random numbers are encrypted by the second encryption processing means using the public key of the first communication device in a public key system. The first and second random numbers transmitted from the second communication means to the first communication device via the network, and the first communication device transmits the encrypted random number transmitted from the second communication device. Receiving the first and second random numbers by the first communication means;
The received first and second random numbers are decrypted by the first encryption processing means using the secret key of the first communication device itself, and the decrypted first random number is stored in the stored first random number. The first encryption key generation means generates an encryption key of a common key system as a session key by a predetermined algorithm using the first and second random numbers, and verifies the same as a session key. The second random number is encrypted by a first encryption processing means using a common key encryption key;
The encrypted second random number is transmitted from the first communication unit to the second communication device via the network, and the second communication device transmits the encrypted second random number transmitted from the first communication device. Receiving the second random number by the second communication means,
In the encryption key generation means of the first and second stored
A cryptographic key of a common key system is generated as a session key by the predetermined algorithm using the random number of The gist is to verify that the decoded second random number is equal to the held second random number.

According to the sixth aspect of the present invention, the first and second communication devices generate an encryption key of a common key system as a session key in their respective arithmetic means, and communicate with the other communication device via a network. The data transmitted and received between the devices is encrypted with the session key and transmitted via the communication means.

According to a seventh aspect of the present invention, in the fifth or sixth aspect, the arithmetic means is configured as an external access prohibition device that can prohibit external access to internal data. I do.

According to the present invention, since the arithmetic means is configured as an external access prohibition device which can prohibit external access to the internal data, a person who can operate the communication device stores the session key. Removal can be prevented.

The present invention according to claim 8 provides the present invention according to claim 7.
In the invention described in the above, when the arithmetic means constituted by the external access prohibiting means outputs internal data to the outside, a digital watermark is inserted into the internal data or the internal data is converted into analog data and output. The gist of the present invention is to have a data processing unit that performs the processing.

According to the present invention, when the internal data of the arithmetic means is output to the outside, the data processing means inserts a digital watermark into the internal data or converts the internal data into analog data. Therefore, it is not possible to acquire data itself without a digital watermark or digital data itself that is not analog data.

Further, the present invention described in claim 9 is the same as claim 7.
In the invention described above, the gist is that the external access prohibiting means is configured by a tamper-resistant device.

According to the ninth aspect of the present invention, the external access prohibiting means is constituted by a tamper-resistant device.

According to a tenth aspect of the present invention, in the invention of the sixth aspect, the second arithmetic means further comprises a corresponding public key obtaining means for obtaining a public key corresponding to the ID of the first arithmetic means. It is the gist to have.

According to the present invention described in claim 10, the first aspect
Since the public key corresponding to the ID of the arithmetic unit is obtained, even if there are a plurality of first communication devices, the ID of the arithmetic unit of the communication device can be obtained accurately.

According to the present invention, there is provided an encryption apparatus for encrypting and transmitting data transmitted between a first communication apparatus and a second communication apparatus via a network so as to protect the data from a third party. A communication method of encrypted data, wherein the first communication device generates a first random number, stores the first random number,
The first communication device uses the public key of the second communication device in a public key manner.
And transmits the encrypted first random number to the second communication device via the network, and the second communication device transmits the encrypted first random number transmitted from the first communication device. Receiving the received first random number, decrypting the received encrypted first random number with its own secret key, generating a second random number, storing the first and second random numbers, The first and second random numbers are encrypted by a public key method using a public key of the first communication device, and the encrypted first and second random numbers are transmitted to the first communication device via a network. Transmitting, the first communication device receives the encrypted first and second random numbers transmitted from the second communication device,
Decrypting the received encrypted first and second random numbers with its own secret key, verifying that the decrypted first random number is equal to the stored first random number, Using a first algorithm and a second random number to generate a common key encryption key as a session key with a predetermined algorithm, encrypting the second random number with a common key encryption key that is the generated session key, The encrypted second random number is transmitted to the second communication device via the network, and the second communication device transmits the encrypted second random number transmitted from the first communication device. Receiving, using the stored first and second random numbers, generating a common key encryption key as a session key using the predetermined algorithm, and generating the received second key using the generated common key encryption key. Decrypts the random number of Second the second random number has the holding
The gist is to verify that the random number is equal to

According to the present invention as set forth in claim 11, the first aspect is as follows.
The communication device generates and stores the first random number, encrypts the first random number by a public key method using the public key of the second communication device, and converts the encrypted first random number into the second And the second communication device decrypts the received encrypted first random number with its own secret key, generates a second random number, and generates the first and second random numbers. The first and second random numbers are stored and encrypted by a public key method using a public key of the first communication device, and the encrypted first and second random numbers are stored in the first communication device.
And the first communication device decrypts the received first and second encrypted random numbers with its own secret key, and the decrypted first random number is stored in the first communication device. It verifies that it is equal to the first random number, generates an encryption key of the common key method as a session key by a predetermined algorithm using the first and second random numbers, and generates the encryption key of the common key method which is the generated session key. Encrypting the second random number with the encryption key, transmitting the encrypted second random number to the second communication device,
The second communication device receives the encrypted second random number,
A common key encryption key is generated as a session key by a predetermined algorithm using the stored first and second random numbers, and a second random number is decrypted with the common key encryption key. Verify that the second random number is equal to the held second random number.

Further, according to the present invention, there is provided a cipher for encrypting and transmitting data transmitted between a first communication device and a second communication device via a network so as to protect the data from a third party. A communication method of encrypted data, wherein the first communication device generates a first random number, stores the first random number,
The ID of the first arithmetic unit of the first communication device itself is obtained, and the obtained ID and the first random number are encrypted by a public key method using the public key of the second communication device. Transmitting the encrypted ID, the first random number, and the unencrypted ID to the second communication device via the network;
The second communication device receives the encrypted ID, the first random number, and the unencrypted ID transmitted from the first communication device, and receives the encrypted I
D, and decrypts the first random number with its own secret key, compares the received unencrypted ID with the decrypted ID, verifies that they are equal, and generates a second random number. , The first and second random numbers are stored, and the first and second random numbers are encrypted by a public key method using a public key of a first communication device, and the encrypted first and second random numbers are encrypted. To the first communication device via the network,
The first communication device receives the encrypted first and second random numbers transmitted from the second communication device, and transmits the received encrypted first and second random numbers to itself. , And verify that the decrypted first random number is equal to the stored first random number.
And a cryptographic key of a common key system is generated as a session key by a predetermined algorithm using the second random number, and the second random number is encrypted by the generated cryptographic key of the common key system.
The encrypted second random number is transmitted to the second communication device via the network, and the second communication device transmits the encrypted second random number transmitted from the first communication device. Receiving, using the stored first and second random numbers, generating a common key encryption key as a session key using the predetermined algorithm, and generating the received second key using the generated common key encryption key. The main point is to verify that the decoded second random number is equal to the held second random number.

According to the present invention described in claim 12, the first aspect
The communication device generates and stores a first random number, obtains an ID of the first arithmetic unit, and stores the ID and the first random number in a second
And encrypts the encrypted ID, the first random number, and the unencrypted ID to the second communication device using the public key of the communication device of the second communication device. Receiving the encrypted ID, the first random number and the unencrypted ID, and receiving the encrypted I
D, and decrypts the first random number with its own secret key, compares the received unencrypted ID with the decrypted ID, verifies that they are equal, generates a second random number, and generates a first random number.
And a second random number are stored, and the first and second random numbers are encrypted by a public key method using a public key of the first communication device,
The encrypted first and second random numbers are transmitted to a first communication device, and the first communication device transmits the encrypted first and second random numbers to the first communication device.
And a second random number, and decrypts the received first and second random numbers with its own secret key.
It verifies that this first random number is equal to the stored first random number, and generates a common key type encryption key as a session key by a predetermined algorithm using the first and second random numbers. Encrypts the second random number with the encryption key of the method,
The second communication device transmits the encrypted second random number to the second communication device, and the second communication device receives the encrypted second random number and converts the stored first and second random numbers. A common key encryption key is generated as a session key using a predetermined algorithm, and the received second random number is decrypted with the common key encryption key. Verify that it is equal to a random number.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a communication system using a communication device for encrypted data according to an embodiment of the present invention. The communication system shown in FIG.
A first communication device 1 including a first communication unit 10 and a first calculation unit 11 and a second communication device 2 including a second communication unit 20 and a second calculation unit 21 are connected via a network 3. Connected, data transmitted and received between the first communication device 1 and the second communication device 2 via the network 3 is encrypted for transmission from a third party and transmitted. In FIG. 1, the communication device for encrypted data of the present invention is applied to a first communication device 1 and a second communication device 2. The communication device is a data communication (transmission / reception)
(Not shown).

The first and second arithmetic means 11, 21 are:
As shown in FIG. 2, each of the secret keys SK1 (SK2: (note) codes and symbols related to the second arithmetic means 21 are shown in parentheses) of the arithmetic means itself and the public key of the partner communication apparatus as shown in FIG. Data holding means 12 (22) for storing data including PK2 (PK1), random number generation means 13 (23) for generating random numbers, encryption processing means 15 (25) for performing encryption processing and decryption processing, and partner communication An encryption key generation means (24) for generating an encryption key of a common key system as a session key from one or more numerical data by a predetermined algorithm shared with the device.

The first arithmetic means 11 and the second arithmetic means 21 are tamper-resistant devices, such as IC cards and tamper-resistant computers, which are configured as external access prohibition devices that can prohibit external access to internal data. The first arithmetic means 11 and the second arithmetic means 11
By using the public key PK generated by each of the calculation means 21 as a session key and encrypting and decrypting the communication data using the encryption processing means 15 and 25 inside the IC card, the session key and the The encrypted communication can be performed without sending the original random number to the outside of the IC card, and the session key can be prevented from being stolen from the first communication device 1 and the second communication device 2. The use of the IC card may be used only when the person operating the first communication device 1 or the second communication device 2 is an unreliable person, and the communication on the side operated only by a reliable person can be used. The calculation means of the device does not need to use an IC card.

Next, the operation of the communication apparatus for encrypted data configured as shown in FIGS. 1 and 2 will be described with reference to the sequence diagram shown in FIG.

First, in the first arithmetic means 11 of the first communication device 1, the first random number generating means 13 (note: the first arithmetic means 11 includes the first word "first" The first random number R1 is generated by using the word “second” at the beginning of the components of the second arithmetic unit 21), and the first random number R1 is converted to the first random number R1. The data is stored in the data holding unit 12 and is stored in the first cryptographic processing unit 15 in the second arithmetic unit 2.
A first random number R1 in a public key system using the first public key PK2.
Is encrypted to XR1, and the encrypted first random number XR1 is transmitted from the first communication means 10 to the second communication device 2 via the network 3 (step S1).

Next, in the second arithmetic means 21 of the second communication device 2, the encrypted first random number XR 1 transmitted from the first communication device 1 is transmitted to the second communication means 2.
0, and the received first random number XR1 is decrypted by the second encryption processing means 25 using its own secret key SK2 to obtain the random number R1. Then, the second random number generating means 23 generates a second random number R2, and stores the first random number R1 and the second random number R2 in the second data holding means 22. The first random number R1 and the second random number R2 are encrypted by the public key method using the public key PK1 of the first communication device 1 to obtain XR2, and the encrypted first and second random numbers R2 are obtained.
From the second communication means 20 to the network 3
(Step S).
3).

Then, the first arithmetic means 11 of the first communication device 1 transmits the encrypted first and second random numbers XR2 transmitted from the second communication device 2 to the first communication device. Means 10 and decrypts the received first and second random numbers XR2 with its own secret key SK1 in a first encryption processing means 15 to obtain a first random number R1 and a second random number XR2. A random number R2 is obtained, and the second random number R2 is stored in the data holding unit 12. Further, the decrypted first random number R1 is the stored first random number R1.
It verifies that it is equal to 1 and authenticates that the other party's communication device is correct. A key-type encryption key is generated as a session key, and this encryption key is set to PK. Then, a second random number R2 is generated using the generated common key encryption key PK.
Is encrypted by the first encryption processing means 15, and the encrypted second random number XR3 is transmitted from the first communication means 10 to the second communication device 2 via the network 3 (step S5).

Next, in the second computing means 21 of the second communication device 2, the encrypted second random number XR3 transmitted from the first communication device 1 is transmitted to the second communication device 2.
0, and then the first random number R1 stored in the second data holding unit 22 in the second encryption key generation unit 24.
Using the second random number R2 and a predetermined algorithm, an encryption key of the common key method is generated as a session key, and this encryption key is set to PK. The received second random number XR3 is decrypted by the second cryptographic processing means 25 using the generated common key type encryption key PK to obtain a second random number R2, and the decrypted second random number is obtained. R2 holds the second
Is verified to be equal to the random number R2, and the other party's communication device is authenticated as being correct (step S7).

Thereafter, the PK generated as described above is shared and used as a session key (step S9). That is, when the first communication device 1 transmits communication data to the second communication device 2, the first communication device 1
The first computing means 11 which has received the data to be transmitted by the transmitting application first encrypts the communication data with the session key and transmits the data to the second communication device 2. Second
When the communication device 2 receives the encrypted communication data, the communication device 2 transmits the encrypted communication data to the second arithmetic unit 2.
At 1, it is decrypted with the session key and passed to the receiving application.

When the second communication device 2 transmits communication data to the first communication device 1, the second communication device 2
The communication data is encrypted by the second computing means 21 using the session key and transmitted to the first communication device 1. When the first communication device 1 receives the encrypted communication data, the first communication device 1 converts the encrypted communication data into first operation means 11.
Decrypts with the session key.

Note that FEEL, DES, or the like can be used as the encryption of the common key method in the above processing, and RAS, elliptic encryption, or the like can be used as the encryption of the public key method, for example.

Next, a communication device for encrypted data according to another embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a block diagram showing a configuration of the first arithmetic unit 110 and the second arithmetic unit 210 used in the encrypted data communication device of the present embodiment. As shown in FIG. 3, the first calculation means 110 and the second
Of the first calculating means 11 shown in FIG.
The second embodiment is different from the first embodiment in that data processing units 16 and 26 are newly added to the second arithmetic unit 21. Other configurations and operations are the same.

In FIG. 2, as described above, the first arithmetic means 11 and the second arithmetic means 21 are connected to each other so as to prohibit external access to the internal data, such as an IC card or a tamper-resistant computer. Although the external access prohibition device which is a tamper device is configured, in the present embodiment of FIG. 3, the encrypted data received by the arithmetic means 110 (210) configured as such a tamper-resistant device is decrypted, and In outputting the data, the data processing means 16 (26) inserts a digital watermark into the decoded data, or converts the decoded data into analog data and outputs it. Therefore, internal data such as received communication data may be illegally obtained as is from outside the tamper-resistant device. It is one that is to be able to Ku use.

That is, as in the present embodiment, the first arithmetic means 110 and the second arithmetic means 210 comprising tamper-resistant devices insert a digital watermark into the internal data or convert the internal data into analog data. Since the data processing means 16 (26) for converting the data into a digital data and outputting the data is provided, a digital watermark is inserted into the data output to the outside, or the data is converted into analog data and output. It cannot be taken out as it is.

Further, in the embodiment shown in FIG. 3, the first calculating means 110 has an ID of the first calculating means itself.
And an ID acquiring means for acquiring
Reference numeral 10 includes a built-in corresponding public key obtaining unit that obtains the public key PKS of the first calculating unit 110 corresponding to the ID (SID) of the first calculating unit 110.

That is, in the present embodiment, when there are a plurality of first calculating means 110, the first calculating means 11
Since there are a plurality of public keys PKS of 0, the second operation means 21
0, it is necessary to obtain the public key PKS corresponding to the SID of the first calculating means 110. For this purpose, the corresponding public key obtaining means is provided.
A public key PKS corresponding to 10 SIDs is obtained.

The corresponding public key obtaining means is composed of, for example, a list of PKS corresponding to the SID of the first calculating means 110, and by referring to this list, the corresponding SID of the first calculating means 110 is obtained. It is possible to obtain the public key PKS.
0, the corresponding first arithmetic means 110
Public key PKS corresponding to the SID can be obtained.

Next, with reference to a sequence diagram shown in FIG. 5, the operation of the encrypted data communication device of the present embodiment will be described.

First, in the first calculating means 110 of the first communication device 1, the first random number generating means 13 generates the first random number R1, and stores the first random number R1 in the first data holding unit. Means 12 and stores the I
D (SID) is acquired by the ID acquisition means built in the first arithmetic means 110, and the acquired SID and the first random number R1 are sent to the first encryption processing means 15 by the public key PK2 of the second communication device 2. And XR1 is obtained by encryption using a public key method, for example, RSA. Then, the encrypted SID, the first random number XR1, and the unencrypted SID are transmitted from the first communication means 10 to the second communication device 2 via the network 3 (step S11).

Next, in the second arithmetic means 210 of the second communication device 2, the encrypted SID and the first random number XR1 transmitted from the first communication device 1 are encrypted. Received by the second communication means 20,
The received encrypted ID and the first random number X
R1 is decrypted by the second encryption processing means 25 using the secret key SK2 of the second communication device 2 itself, and a first random number R1 and SID are obtained. Then, compare the decrypted SID with the unencrypted SID received in plaintext,
Verify that they are equal. Next, the second random number R2 is generated by the second random number generation means 23, and the first random number R2 is generated.
The first and second random numbers R2 are stored in the second data holding unit 22. Further, a public key PK1 of the first arithmetic means 110 corresponding to the SID of the first arithmetic means 110 is obtained, and the obtained public key PK1 of the first arithmetic means 110 is used to obtain a second encryption processing means. At 25, the first random number R1 and the second random number R2 are encrypted by a public key method, and XR2
And the encrypted first and second random numbers XR
2 is transmitted from the second communication means 20 to the first communication device 1 via the network 3 (step S13).

Next, the first computing means 1 of the first communication device
10, the first communication means 10 receives the encrypted first and second random numbers XR2 transmitted from the second communication device 2 and receives the encrypted first and second random numbers XR2. The second random number XR2 is converted to the first cryptographic processing unit 15
Decrypts with the secret key SK1 of the first communication device itself, and verifies that the decrypted first random number R1 is equal to the stored first random number. Then, the first encryption key generation means 14 generates a common key encryption key as a session key PK by a predetermined algorithm using the first random number R1 and the second random number R2. The second random number R2 is encrypted by the first encryption processing means 15 using the encryption key PK of the second encryption key PK.
From the first communication means 10 to the network 3
(Step S1).
5).

Then, in the second calculating means 210 of the second communication device 2, the encrypted second random number XR 3 transmitted from the first communication device 1 is converted by the second communication means 20. The second encryption key generation means 24 generates a common key encryption key as a session key PK by a predetermined algorithm using the stored first random number R1 and second random number R2 in the second encryption key generation means 24. The received second random number R2 is decrypted by the second encryption processing means 25 using the common key type encryption key PK, and it is determined that the decrypted second random number R2 is equal to the held second random number. Verification is performed (step S17).

Thereafter, the PK generated as described above is shared and used as a session key (step S19).
That is, when the first communication device 1 transmits communication data to the second communication device 2, the first arithmetic unit 110 of the first communication device 1 first encrypts the communication data with the session key, and 2 communication device 2. When the second communication device 2 receives the encrypted communication data,
The encrypted communication data is decrypted by the second arithmetic means 210 using the session key.

When the second communication device 2 transmits communication data to the first communication device 1, the second communication device 2
The communication data is encrypted with the session key in the second arithmetic means 210 and transmitted to the first communication device 1. When the first communication device 1 receives the encrypted communication data, the first communication device 1 converts the encrypted communication data into first operation means 11.
At 0, it is decrypted with the session key.

In the above-mentioned processing, for example, FEAL or DES can be used as the encryption of the common key system, and as the encryption of the public key system, for example, RSA or elliptic encryption can be used.

[0056]

As described above, according to the present invention,
The communication device generates an encryption key of the common key method as a session key in the arithmetic means, encrypts data transmitted and received between the communication device and the other communication device via the network with the session key, transmits the data through the communication means, and calculates Since the means is constituted by an external access prohibition device capable of prohibiting external access to the internal data, it is possible to prevent a person who can operate the communication device from extracting the session key.

Further, according to the present invention, since the internal data of the arithmetic means is inserted with a digital watermark by the data processing means or converted into analog data and outputted, the data itself without the digital watermark or the analog data is output. Digital data itself that is not data cannot be obtained.

Further, according to the present invention, the I
Since D is obtained and the public key corresponding to the ID of the arithmetic unit is obtained, even if there are a plurality of communication devices, the ID of the arithmetic unit of the communication device can be obtained accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a communication system using an encrypted data communication device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of first and second calculation means used in the encrypted data communication device of the embodiment shown in FIG. 1;

FIG. 3 is a block diagram showing a configuration of first and second calculation means used in a communication device for encrypted data according to another embodiment of the present invention.

FIG. 4 is a sequence diagram showing the operation of the communication device for encrypted data of the embodiment shown in FIG. 1;

FIG. 5 is a sequence diagram showing an operation of the communication device for encrypted data of the embodiment shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st communication apparatus 2 2nd communication apparatus 3 network 10 1st communication means 11 1st arithmetic means 12 (22) data holding means 13 (23) random number generation means 14 (24) encryption key generation means 15 ( 25) encryption processing means 16 (26) data processing means 20 second communication means 21 second calculation means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B017 AA03 BA07 5J104 AA01 AA14 EA19 EA26 JA03 NA02 NA42 PA07 5K030 GA15 HA08 HB18 HC01 KA01 KA06 LA07 LD19 LD20 LE11

Claims (12)

[Claims] 1. An encrypted data communication apparatus for encrypting and transmitting data mutually transmitted and received between a communication apparatus and a communication apparatus via a network to protect the data from being transmitted to a third party. Communication means for transmitting and receiving data to and from the communication means; and data holding means for storing data including a secret key of the calculation means itself and a public key of the partner communication device; Random number generation means for generating, encryption processing means for performing encryption processing and decryption processing, and 1 using a predetermined algorithm shared with the partner communication apparatus.
First arithmetic means including an encryption key generation means for generating an encryption key of a common key system from one or more numerical data, wherein the arithmetic means is capable of prohibiting external access to internal data. A communication device for encrypted data, wherein the communication device is configured as a prohibition device. 2. The arithmetic means configured as the external access prohibition device inserts a digital watermark into the internal data or converts the internal data into analog data before outputting the internal data. The communication device for encrypted data according to claim 1, further comprising a data processing unit that performs the processing. 3. The communication device for encrypted data according to claim 1, wherein said external access prohibition device comprises a tamper-resistant device. 4. The operation means has an ID of the operation means itself.
2. The encrypted data communication device according to claim 1, further comprising: an ID acquisition unit that acquires a public key corresponding to the ID of the calculation unit. 5. An encrypted data communication device for encrypting and transmitting data transmitted and received between a first communication device and a second communication device via a network so as to protect the data from a third party, The first communication device is connected to a network, transmits first data to the network or receives data from the first network, and a first communication device connected to the first communication device. A first data holding means for storing data including a secret key of the first calculation means itself and a public key of a second communication device; a first data generating means for generating a first random number Random number generation means, first encryption processing means for performing encryption processing and decryption processing, and a common key method from one or more numerical data by a predetermined algorithm shared by the first and second arithmetic means. The encryption key A first operation unit including a first encryption key generation unit for generating a session key, wherein the second communication device is connected to a network and transmits data to the network, or A second communication unit for receiving data from the network, a second operation unit connected to the second communication unit, wherein the secret key of the second operation unit itself and the first communication device A second data holding unit for storing data including a public key; a second encryption processing unit for performing an encryption process and a decryption process; a second random number generation unit for generating a second random number; Second arithmetic means including second encryption key generation means for generating a common key encryption key as a session key from one or more numerical data by a predetermined algorithm shared by the two arithmetic means. Then The first communication device generates the first random number by the first random number generation means, stores the first random number in the first data holding means, and makes the first encryption processing means release the second communication device. Encrypting a first random number by a public key method using a key, transmitting the encrypted first random number from a first communication means to a second communication device via a network, Receives the encrypted first random number transmitted from the first communication device by a second communication means, and receives the encrypted first random number from a second encryption processing means. Decrypts with its own secret key, generates a second random number with a second random number generating means, stores the first and second random numbers in a second data holding means, and generates a second random number in a second encryption processing means. Encrypting the first and second random numbers by a public key method using a public key of the first communication device; Transmitting the encrypted first and second random numbers from the second communication means to the first communication device via the network, wherein the first communication device transmits the first and second random numbers from the second communication device. The encrypted first and second random numbers are received by the first communication means, and the received encrypted first and second random numbers are decrypted by the first encryption processing means using their own secret keys. It verifies that the decrypted first random number is equal to the stored first random number, and uses a first algorithm and a second random number in a first encryption key generation means to generate a common key using a predetermined algorithm. A second encryption method generates a second encryption key as a session key, encrypts the second random number with the generated encryption key of the common key scheme in a first encryption processing unit, and converts the encrypted second random number into a first encryption key. The second communication from the communication means via the network The second communication device receives the encrypted second random number transmitted from the first communication device by a second communication unit, and the second communication key generation unit transmits the encrypted second random number to the second encryption key generation unit. Using the first and second random numbers stored in the second data holding means, a common key encryption key is generated as a session key by the predetermined algorithm, and the reception key is generated by the generated common key encryption key. The decrypted second random number is decrypted by the second encryption processing means, and the decrypted second random number is stored in the stored second random number.
A communication device for encrypted data, wherein the communication device verifies that the random number is equal to the random number. 6. An encrypted data communication device for encrypting and transmitting data transmitted and received between a first communication device and a second communication device via a network so as to protect the data from a third party, The first communication device is connected to a network, transmits first data to the network or receives data from the first network, and a first communication device connected to the first communication device. A first data holding means for storing data including a secret key of the first calculation means itself and a public key of a second communication device, and an ID of the first calculation means itself. ID acquisition means for acquisition, first random number generation means for generating a first random number, first encryption processing means for performing encryption processing and decryption processing, and the first and second arithmetic means are shared Have given al A first calculating means including a first encryption key generating means for generating an encryption key of a common key system as a session key from one or more numerical data in rhythm; and wherein the second communication device comprises a network. And a second communication means connected to the second communication means for transmitting data to the network or receiving data from the network; and a second arithmetic means connected to the second communication means, A second data holding unit for storing data including a secret key of the second operation unit itself and a public key of the first communication device; a second encryption processing unit for performing an encryption process and a decryption process; A second random number generating unit for generating a random number, a second algorithm for generating a common key encryption key as a session key from one or more numerical data by a predetermined algorithm shared by the first and second arithmetic units; A second operation unit including an encryption key generation unit, wherein the first communication device generates a first random number by the first random number generation unit, and stores the first random number in a first data storage Means, and the ID of the first arithmetic means itself is obtained by the ID obtaining means, and the obtained ID and the first random number are used in the first encryption processing means by using the public key of the second communication device. And encrypts the encrypted ID and the first
Transmitting the random number and the unencrypted ID from the first communication means to the second communication device via the network, and the second communication device transmits the encrypted ID transmitted from the first communication device. The received ID, the first random number and the unencrypted ID are received by the second communication means, and the received encrypted ID and the first random number are received by the second encryption processing means for the second communication. Decrypt with the device's own private key,
The received unencrypted ID and the decrypted ID are compared to verify that they are equal, a second random number is generated by second random number generation means, and the first and second random numbers are generated. Is stored in the second data holding means, and the first and second random numbers are encrypted in the second encryption processing means using the public key of the first communication device by a public key method. Transmitting the first and second random numbers from the second communication means to the first communication device via the network, wherein the first communication device transmits the encrypted first random number transmitted from the second communication device; And the second random number is received by the first communication means, and the received first and second random numbers are decrypted by the first encryption processing means using the secret key of the first communication device itself. The decoded first random number is the stored first random number. The first encryption key generation means generates an encryption key of the common key method as a session key by a predetermined algorithm using the first and second random numbers, and generates the generated common key method. Encrypting the second random number in the first encryption processing means with the encryption key, transmitting the encrypted second random number from the first communication means to the second communication device via the network; The second communication device receives the encrypted second random number transmitted from the first communication device by a second communication unit, and stores the stored first and second random numbers in the second encryption key generation unit. Using a second random number to generate a common key cryptographic key as a session key by the predetermined algorithm, and using the generated common key cryptographic key to convert the received second random number to a second cryptographic processing means And decrypt this An encrypted data communication device for verifying that a decrypted second random number is equal to the held second random number. 7. The encrypted data communication device according to claim 5, wherein the arithmetic unit is configured as an external access prohibition device that can prohibit external access to the internal data. 8. The arithmetic means constituted by the external access prohibiting means, when outputting the internal data to the outside, inserts a digital watermark into the internal data or converts the internal data into analog data and outputs the data. The communication device for encrypted data according to claim 7, further comprising a data processing unit that performs the data processing. 9. The communication device for encrypted data according to claim 7, wherein said external access prohibition means comprises a tamper-resistant device. 10. The apparatus according to claim 6, wherein said second calculating means further comprises a corresponding public key obtaining means for obtaining a public key corresponding to an ID of said first calculating means. Communication device. 11. A method for communicating encrypted data, wherein data transmitted between a first communication device and a second communication device via a network is encrypted to protect the data from a third party and transmitted. The first communication device generates a first random number, stores the first random number, and uses the public key of the second communication device in a public key manner.
And transmits the encrypted first random number to the second communication device via the network. The second communication device transmits the encrypted first random number transmitted from the first communication device. Receiving the received first random number, decrypting the received encrypted first random number with its own secret key, generating a second random number, storing the first and second random numbers, The first and second random numbers are encrypted by a public key method using a public key of a first communication device, and the encrypted first and second random numbers are transmitted to a first communication device via a network. The first communication device receives the encrypted first and second random numbers transmitted from the second communication device, and receives the encrypted first and second random numbers. The random number is decrypted with its own secret key, and the decrypted first random number is The first and second random numbers are used to generate a common key cryptographic key as a session key by a predetermined algorithm using the first and second random numbers. Encrypting the second random number with a cryptographic key of a system, transmitting the encrypted second random number to a second communication device via a network, wherein the second communication device Receiving the transmitted encrypted second random number, using the stored first and second random numbers to generate a common key encryption key as a session key with the predetermined algorithm, The received second key using the common key encryption key
A method of communicating encrypted data, comprising: verifying that the second random number decrypted is equal to the second random number held. 12. A method of communicating encrypted data, wherein data transmitted between a first communication device and a second communication device via a network is encrypted to be protected from a third party and transmitted. The first communication device generates a first random number, stores the first random number, obtains an ID of a first calculation unit of the first communication device itself, and obtains the obtained ID and the The first random number is encrypted by a public key method using the public key of the second communication device, and the encrypted ID, the first random number, and the unencrypted ID are transmitted to the second communication device via a network. And the second communication device transmits the encrypted I transmitted from the first communication device.
D and a first random number and an unencrypted ID are received, and the received encrypted ID and the first random number are decrypted with its own secret key, and the received unencrypted ID and The decrypted IDs are compared to verify that they are equal, a second random number is generated, the first and second random numbers are stored, and the first and second random numbers are The communication device encrypts the first and second random numbers using a public key method using a public key of the communication device, and transmits the encrypted first and second random numbers to the first communication device via a network. Receiving the encrypted first and second random numbers transmitted from the communication device, and decrypting the received encrypted first and second random numbers with its own secret key. The converted first random number is equal to the stored first random number The first and second random numbers are used to generate a common key encryption key as a session key using a predetermined algorithm, and the second random number is generated using the generated common key encryption key. Transmitting the encrypted second random number to a second communication device via a network, wherein the second communication device transmits the encrypted second random number transmitted from the first communication device. Using the stored first and second random numbers to generate a common key cryptographic key as a session key using the predetermined algorithm, and using the generated common key cryptographic key to perform the reception. Second
A method of communicating encrypted data, comprising: verifying that the second random number decrypted is equal to the second random number held.