JP2002281475A - Image pickup device, server device and client device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device capable of eliminating alteration of image data, a server device and a client device. SOLUTION: This image pickup device 100 having identifier information and a first encryption expression in each sold body, performs hash function processing of picked up image data to acquire a hash value, enciphers the acquired hash value by using the first encryption expression and transmits the enciphered hash value to the server device 300 via the client device 200. The server device 300 acquires the original hash value with a prescribed decoding expression, signs the original hash value with a second encryption expression and transmits the signed hash value to the client device 200. The client device 200 compares a hash value acquired from the image data by the client device 200 itself with the original hash value to confirm the existence/non-existence of image data alteration. The original hash value is decoded with a third encryption expression to be verified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device, a server device, and a client device. More specifically, the present invention relates to an electronic mail message transmitted via a network, which encrypts a message including image data using a plurality of key information. The present invention relates to an imaging device, a server device, and a client device capable of discovering and eliminating tampering of the message by performing encryption and decryption.

[0002]

2. Description of the Related Art In recent years, various types of information are available through the Internet.
The exchange of (messages) has become more frequent. At the same time, there is an increasing risk that hackers can break into mail servers and clients, read other people's mails and exploit the information, or falsify them and cause confusion. Under these circumstances, in recent years, not only text messages but also messages containing a lot of image data or messages consisting of image data have been transmitted and received, and even if fine parts of the image data have been tampered with, it has been discovered Some cases are getting harder to do. Apart from such a situation, an electronic verification technique has been conventionally developed to eliminate tampering. In the system according to this technology, a sender A of a message transmits the message to a recipient B and also transmits the message to a certificate authority C, and the recipient B communicates with the content of the message directly received from the sender A via the certificate authority C. And verifies whether or not the message content has been tampered with. More specifically, the sender A puts a message to be transmitted into a hash function and obtains a hash value of the message. The obtained hash value is encrypted using the secret key, attached to the message as an electronic signature value, and transmitted to the receiver B. Further, the digital signature value is transmitted to the certificate authority C, and the certificate authority C transmits the digital signature value, the certificate of the sender A issued by the certificate authority C, and the public key to the receiver B as a set. The receiver B obtains a hash value by putting the message directly obtained from the sender A into a hash function and obtains a hash value by decrypting the electronic signature value transmitted from the certificate authority C with the transmitted public key. . Then, these hash values are compared with each other to determine whether the message has been tampered with.

[0003]

However, the above-mentioned prior art is a technique developed mainly with a message of characters in mind, and in the case of message data containing a large amount of image data or consisting of image data, various types of key information are used. Is so simple that even if the image data has been tampered with, the tampering cannot be eliminated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to encrypt and decrypt a message composed of image data in an e-mail message transmitted via a network using a plurality of key information. Accordingly, an object of the present invention is to provide an imaging device, a server device, and a client device capable of eliminating the falsification of the message.

[0005]

According to a first aspect of the present invention, there is provided an image pickup apparatus having different identifier information and a first encryption formula for each image pickup apparatus. An imaging apparatus comprising: means for acquiring a value; and means for encrypting the acquired hash value using the first encryption formula.

According to a second aspect of the present invention, there is provided the imaging apparatus according to the first aspect, wherein the first encryption type cannot be read from the imaging apparatus.

According to a third aspect of the present invention, there is provided means for receiving identifier information of an imaging apparatus and a hash value encrypted by the apparatus using a first encryption formula, and a predetermined decryption method including specific setting information. Means for generating the first encryption formula by a formula, and a means for decrypting the hash value received by the generated first encryption formula to obtain the original hash value. is there.

According to a fourth aspect of the present invention, in the server device of the third aspect, there is provided means for generating signature information by encrypting the obtained original hash value by a second encryption formula set in the server device. A server device characterized by the following.

According to a fifth aspect of the present invention, in the server device according to the third aspect, the specific setting information and the second encryption expression cannot be read from the server device. .

According to a sixth aspect of the present invention, there is provided means for receiving, from a server device, signature information obtained by encrypting an original hash value obtained by decrypting a hash value created by an imaging device, and transmitting the signature information to a third encryption device. A client device comprising means for decoding by a formula to obtain an original hash value.

According to a seventh aspect of the present invention, in the client device according to the sixth aspect, a means for receiving image data from the imaging device, a means for obtaining a hash value from the received image data, A client device having means for comparing with an original hash value.

[0012]

Embodiments of the present invention will be described below. FIGS. 1 and 2 are diagrams showing an environment of a verification system to which the present invention is applied. A message of image data created by a digital camera 100 (sender) is directly transmitted from the camera via a network (not shown). Or the verification client (recipient) 200 via another personal computer 400
Sent to. Further, the message is transmitted to the verification client 200 via the verification server (verification station) 300 in order to verify whether the message has been tampered with. At this time, the verification server 300 is protected by the firewall 500 so as to prevent the hackers or the like from invading itself (FIG. 2).

FIG. 3 is a flowchart of processing and data according to the embodiment of the present invention, and FIG. 4 is a block diagram of a digital camera, a verification client, and a verification server according to the embodiment of the present invention. Hereinafter, the operation of the verification system will be described based on FIGS. The digital camera 100 corresponding to the sender of the message introduces an image signal of the subject formed by the lens and the CCD into the image forming unit 111 through the reception interface (reception I / F) 114 to generate image data image. The digital camera 100 stores an identifier id_a assigned to each camera and an individual key ki_a different for each camera in the storage device 113. The individual key ki_a is stored as encryption formula information represented by a specific function formula. Here, the individual key ki_a is represented by the function expression ki_
a = Enc (km, id_a) is defined. In addition,
km is setting information such as a specific numerical value, for example, as a master key of the verification server 300 described later. Therefore, if the master key km and the identifier id_a are known, the individual key ki_a can be created. Also, the individual key ki_a remains in the storage device 113 and is protected from being externally readable.

The image data image formed by the image forming unit 111 is put into a hash function by a data processing unit 112 to obtain a hash value hash, and this hash value is further obtained by an individual key ki_a called from the storage device 113. Check = Enc (ki_a, hash (ima)
ge)) and convert it into data. The check data is further transmitted to an M suitable for transmission over the Internet.
The AC value mac is calculated again. The MAC value mac obtained in this way is added to the image data imaze by the data processing unit 112 together with the identifier id_a.
The data is transmitted to the verification client 200 via the transmission I / F 115 as a. Note that a series of these processes are controlled by the CPU 110 according to a predetermined program.

In the verification client 200, the reception I / F 211
When the message 100a is received via the
At 212, the image data imaze, the MAC value mac, and the identifier id_a are separated, and the image data image is temporarily stored in the storage device 214 for verification described later. Identifier id_
a and the MAC value mac are transmitted to the verification server 300 via the transmission I / F 213 for verification.

Here, the operation of the verification server 300 will be described. Upon receiving the identifier id_a and the MAC value mac from the verification client 200 via the reception I / F 311, the verification server 300 first separates the MAC value mac and the identifier id_a in the reception signal processing unit 312 and stores them in the storage device 314. I do. Storage device 3
Reference numeral 14 denotes a master key information km as specific setting information, such as a specific numerical value, and a functional expression ki_a = Enc (km, id_a) of the individual key ki_a including the master key information.
A function expression H of a secret key kpriv, an individual key, and a MAC value to be described later.
ash = Dec (ki_a, mac), hash value and secret key kpr
The function formula sig = Sig (kpriv, hash) with iv is stored. Next, the data processing unit 313 calls the stored identifier id_a and the master key km, and obtains the function expression ki_a = Enc (km, km,
The individual key ki_a is generated from id_a). Data processing unit
313 is a function formula of the individual key and the MAC value, Hash = Dec
Get the original hash value hash from (ki_a, mac). Further, the data processing unit 313 calls the secret key kpriv from the storage device 314 to give a signature to the obtained hash value hash, and a functional expression sig of the hash value hash and the secret key kpriv
= Acquire signature information sig from Sig (kpriv, hash).
The hash value hash and the signature information sig are stored in the transmission I / F3
15 to the verification client 200. These series of processes are executed by the CPU 310 according to a predetermined program.

The operation of the verification client 200 will be described again.
The signature information sig and the hash value hash are received via the reception I / F 211 from the server, and are introduced into the data processing unit 215. Here, since the received signal processing unit 212 has already received the image data image and stored it in the storage device 214, the data processing unit 215 calls it, puts it in the hash function, and outputs the hash value hash (image_1). get. And this hash value h
ash (image_1) is compared with the original hash value hash obtained from the verification server 300, and if they are the same, it is determined that the data has not been tampered with in the process of transmitting the image data. Judge that it was done. On the other hand, the storage device 214 stores the public key kpub. The public key kpub is paired with the private key kpriv. By using the public key kpub, only the data signed with the private key kpriv of the server 300 can be represented by the function formula sig = Sig (kpriv, hash). Can be decrypted from
Therefore, the data processing unit 215 sends the public key kpub from the storage device 214.
And decrypts the received signature information sig to obtain a hash value hash. Then, it confirms that this hash value has been transmitted from the verification server 300, and verifies the result of the falsification determination. A series of these processes is performed by CP
U210 executes according to a predetermined program.

FIGS. 5 and 6 are flowcharts showing the procedure of the verification system according to the present invention. The operation of the verification system described with reference to FIGS. 3 and 4 will be described with reference to this flowchart. The digital camera (FIG. 5) captures a subject, generates image data (S11), and creates image data D1.
This image data is put into a hash function to obtain a hash value, which is encrypted with an individual key embedded in the digital camera (S12) to create a MAC value d2. The image data d1 and the MAC value D2 are stored in the verification client 200
Sent to.

The verification client 200 reads the MAC value D2 in response to the data transmission call (FIG. 6) (S2).
1) Then, the image data D1 is read (S22).
The read MAC value is transmitted to the verification server 300 (S
23). The read image data is put into a hash function to obtain a hash value (S24).

Here, an operation flow in the verification server 300 will be described. The verification server 300 receives the MAC value in response to the call from the verification client 200 (S
25), from the MAC value, the identifier IDi of the digital camera 100
d_a is acquired (S26). Based on the identifier IDid_a, the individual key ki_a is obtained from ki_a = Enc (km, id_a).
Is created (S27). MA by the created individual key ki_a
The C value is decrypted to obtain a hash value hash (S28).
This hash value hash is signed (encrypted) with the secret key kpriv to create signature information (S29). The hash value hash and signature information sig created in this way are
(S30).

Returning to the verification client 200, the verification client 200 receives the hash value hash and the signature information sig from the server 300 (S31), and receives the received hash value hash.
It is checked whether or not the signature information sig is the processing result of the transmitted MAC value (S23) (S32). If it is not the processing result of the transmitted Mac value (S23) (S32,
NG), the verification processing is canceled. If it is the processing result of the transmitted Mac value (S23) (S32, O
K), hash value hash calculated by the verification client 200
It is checked whether (image_1) is the same as the hash value hash received from the server 300 (S33). If not the same (S33, NG), the verification processing is canceled. If they are the same (S33, OK), the signature information is obtained using the public key kpub.
It is checked whether the hash value by sig is valid (S3
4) If not valid (S34, NG), an error message is displayed, and if valid, the verification ends.

The above verification processing is performed by the verification client 200
And a software system mounted on each computer of the verification server 300. 7 and 8
Shows their software diagrams. FIG. 7 is a software diagram of the computer of the verification client, and there is an application protocol corresponding to each application located at the highest layer of the OSI. The proof server that performs various proof work has MAC
There are applications that support communication systems such as value reception and transmission of hash values, encryption and decryption of image data using individual keys, and applications for creating signatures using public keys.
As a communication system application protocol, there is a servlet engine, a WWW server, and TCP / TP which is a basic protocol of the Internet. These will be run by the OS. FIG. 8 is a software diagram of a verification client. There is a communication protocol for transmitting and receiving various information on the Internet corresponding to the verification client application. Software etc. which is responsible for input / output of the information is set.

According to the present embodiment, the digital camera 100
Creates an ash value of the image data (image data) using the individual key and the identifier, and transmits the ash value to the verification server 300. The verification server 300 decrypts the individual key ki_a based on the master key km and the identifier information, thereby receiving the key. The original hash value is obtained from the hash value. Since the original hash value is obtained by multiple key operations in this way,
The original hash value is strictly protected at the verification server. In addition, since this is further encrypted with the secret key kpriv and sent to the verification client 200 and verified with the public key kpub, data tampering can be strongly eliminated.

[0024]

According to the first and second aspects of the present invention, a hash value processing is performed on the captured image data to obtain a first hash value.
When the hash value is transmitted via a network, it is difficult to falsify the hash value. Since the first encryption formula functions as a secret individual key, it cannot be searched by others and is useful for eliminating falsification of image data. Effects corresponding to claims 3, 4, and 5:
The hash value encrypted and transmitted from the imaging device is:
Since the first encryption expression is decrypted by the predetermined decryption expression including the specific setting information and the original hash value is obtained, the falsification of the hash value itself can be more strongly excluded. In this case, the specific setting information cannot be searched by others, and is useful for eliminating tampering. Further, since the original hash value is further encrypted by the second encryption formula and is generated as signature information, it is possible to verify that the original hash value has been decrypted in the server device. Advantageous Effects According to Claims 6 and 7: Since the original hash value is obtained by decrypting the signature information received from the server device by the third encryption formula, the original hash value is decrypted in the server device. Can be verified. In this case, by making the third encryption formula function as a public key, the tamper elimination effect can be improved. Further, by comparing the hash value with the hash value directly received and obtained by the client device, falsification of the image data can be found, and the data can be strongly excluded.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a network environment to which the present invention is applied.

FIG. 2 is a schematic configuration diagram of a network environment to which the present invention is applied.

FIG. 3 is a flow chart of a verification process and data according to the present invention.

FIG. 4 is a block diagram of a digital camera, a verification client, and a verification server according to the present invention.

FIG. 5 is a flowchart of an image data verifying operation according to the present invention.

FIG. 6 is a flowchart of an image data verifying operation according to the present invention.

FIG. 7 is a diagram showing a software configuration of a verification server according to the present invention.

FIG. 8 is a diagram showing a software configuration of a verification client according to the present invention.

[Explanation of symbols]

100 digital camera, 200 client
300 verification server, 400 other PC

Claims (7)

[Claims] 1. An image capturing apparatus having different identifier information and a first encryption formula for each image capturing apparatus, means for performing hash function processing on captured image data to obtain a hash value, An image capturing apparatus having means for encrypting the data by using the first encryption formula. 2. The imaging apparatus according to claim 1, wherein the first encryption type cannot be read from the imaging apparatus. 3. A means for receiving identifier information of an imaging device and a hash value encrypted using a first encryption formula in the device, and the first decryption formula including a predetermined decryption formula including specific setting information. Means for generating an encryption expression of
A server device comprising means for decrypting a hash value received by an encryption formula of (1) and obtaining an original hash value. 4. The server device according to claim 3, wherein
The second that the acquired original hash value is set in the server device
Characterized in that the server device has means for generating signature information by encrypting according to the encryption formula. 5. The server device according to claim 3, wherein
The server device, wherein the specific setting information and the second encryption expression cannot be read from the server device. 6. A means for receiving signature information obtained by encrypting an original hash value obtained by decrypting a hash value created by an imaging device from a server device, and decrypting the signature information by a third encryption formula. A client device having a means for obtaining an original hash value by using the client device. 7. The client device according to claim 6, wherein: means for receiving image data from the imaging device; means for obtaining a hash value from the received image data; Characterized in that the client device has means for comparing