JP3885882B2 - Image forming apparatus and image forming system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that receives data to be kept secret and forms an image represented by the data on a sheet, and an image forming system including the image forming apparatus.
[0002]
[Prior art]
2. Description of the Related Art In recent years, the use of a LAN in which a local area network (LAN) is a system that conforms to the Internet's Web system is rapidly spreading, and a series of processes for creating data and printing (forming a sheet as an image). In addition, a system compliant with the Web system has been proposed. Some data to be printed should be kept secret, and such data needs to be managed in the same manner as a printed image. Even if the data itself should not be kept secret, in order to guarantee the contents of the printed data, a seal or signature is often printed, and the data representing the seal or signature must be managed confidentially.
[0003]
As a method for maintaining the confidentiality of data, it is proposed to set a password for data, send the password from the computer to the printer together with the data, and print only when the user enters the correct password in the printer (For example, refer to Patent Document 1).
[0004]
[Patent Document 1]
JP-A-9-65148
[0005]
[Problems to be solved by the invention]
However, although it is unlikely that a person who does not know the correct password will enter the correct password, there is a possibility that the correct password will be input by chance or trial and error, and the method of identifying the printer user by password remains. Confidentiality is not perfect. Moreover, in a Web system or a system based on this, in addition to a server that creates data and a printer that prints an image represented by the data, there are a number of devices connected to the data transmission path, and the data is independent of the password. There is a possibility to access.
[0006]
For example, a personal computer connects to a server via a Web browser, requests creation of data, receives the created data, and can access data cached in the browser from another device. Although there is a cache prohibition command in the HTTP protocol, whether or not to prohibit the cache depends on the implementation of the browser and is uncertain. Further, data can be accessed through a transmission path from the personal computer to the printer unless the printer is connected to the personal computer with a dedicated cable.
[0007]
Conventionally, in facsimile communication, data that should be kept confidential is encrypted by a transmission-side device, and the reception-side device decrypts the data to reproduce the data before encryption. This encrypted transmission can also be used to ensure the confidentiality of data. For encrypted transmission, encryption and decryption are performed with the same key, and each key is kept secret, and encryption and decryption are performed with different keys (paired with each other), There is a public key method in which only the key for decryption is kept secret and the key for encryption is made public.
[0008]
When performing encrypted transmission of data to be printed by a Web system or a system conforming thereto, if the encryption key is stored in the server on the transmission side, there is a possibility that the key may be accessed from another device. Therefore, when the encryption key is stored in the server on the transmission side, the encryption key is not a secret key (a key that needs to be kept secret) but a public key (a key that may be disclosed). It is necessary to adopt the public key method instead of the common key method. However, even if the public key method is adopted, if the key for decryption is stored in the printer, there is a possibility that the key is accessed from another device, and the confidentiality cannot be ensured.
[0009]
If the encryption key is not stored in the server and the decryption key is not stored in the printer, a common key method can be adopted. In other words, the server can use the common key when performing encryption, and the printer can use the common key when performing decryption. This can be easily realized by allowing the user to input a common key to the server or printer. However, it is complicated to input a common key to both the server and the printer, and it is often difficult to input the common key to the server when the server is in a remote place. If a common key is input to a personal computer and transmitted to a server or a printer, the complexity and difficulty of input can be avoided. However, by doing so, there is a possibility that the common key can be accessed from another device on the transmission path.
[0010]
SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and a simple image forming apparatus capable of reliably keeping confidential information among data representing an image formed on a sheet, and an image An object is to provide a forming system.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a storage medium storing a secret key in an image forming apparatus that receives encrypted data and decrypts the data and forms an image represented by the decrypted data on a sheet. A reading means for reading the secret key and a decryption means for decrypting the data with the secret key read by the reading means given the data encrypted with the public key corresponding to the secret key, and decryption The means includes forming means for forming an image represented by the decrypted data on the sheet.
[0012]
This image forming apparatus uses a secret key to decrypt the encrypted data, but the secret key is not stored in the image forming apparatus itself, but is stored in a removable storage medium. Each time decryption is performed, the data is read from the attached storage medium. Therefore, the decryption secret key cannot be accessed from another device, and the decryption secret key is securely kept secret, and as a result, the confidentiality of the data is ensured. The storage medium storing the secret key may be managed by an authorized user responsibly.
[0013]
The image forming apparatus further includes a storage unit storing a secret key, and the decryption unit includes a public key corresponding to the secret key read by the reading unit and a public key corresponding to the secret key stored in the storage unit. And the encrypted data can be decrypted with the secret key read by the reading means and the secret key stored in the storage means.
[0014]
In this way, the data is given to the image forming apparatus in a double-encrypted state, and confidentiality is further increased. The image forming apparatus stores one private key for decryption, but even if this private key can be accessed from the other apparatus, the other private key cannot be accessed and the data Confidentiality is ensured.
[0015]
In order to achieve the above object, the present invention also provides a storage storing a secret key in an image forming apparatus that receives encrypted data, decrypts the data, and forms an image represented by the decrypted data on the sheet. The reading means that reads the secret key with the medium attached, the data encrypted with the common key, and the secret key that is read by the reading means given the common key encrypted with the public key corresponding to the secret key Decrypting means for decrypting the common key, decrypting the data with the decrypted common key, and forming means for forming an image represented by the data decrypted by the decrypting means on the sheet.
[0016]
This image forming apparatus uses the same common key as the key used for encryption in order to decrypt the encrypted data, but the common key is not stored by the image forming apparatus itself. It is given to the image forming apparatus together with the data. Since the given common key is encrypted, the common key is kept secret even if it can be accessed from another device. A secret key is used to decrypt the common key, but this secret key is not stored in the image forming apparatus itself, but is stored in a removable storage medium and decrypted each time it is decrypted. Read from the installed storage medium. Therefore, the secret key for decrypting the common key cannot be accessed from another device, and the secret key and the common key are securely kept secret, and as a result, the confidentiality of the data is ensured.
[0017]
The image forming apparatus further includes a storage unit that stores a secret key. The decryption unit stores data encrypted with the common key, a public key corresponding to the secret key read by the reading unit, and a storage unit. Given a common key encrypted with the public key corresponding to the private key being read, the common key is decrypted with the private key read by the reading means and the private key stored in the storage means and decrypted. The data can be decrypted with the common key.
[0018]
In this way, the common key is given to the image forming apparatus in a double-encrypted state, further improving confidentiality. The image forming apparatus stores one secret key for decrypting the common key, but even if this secret key can be accessed from another apparatus, the other secret key cannot be accessed. The secret key is surely kept secret and the confidentiality of the data is ensured.
[0019]
In order to achieve the above object, in the present invention, an image forming system is constituted by the above-described image forming apparatus and a data providing apparatus for giving data to the image forming apparatus.
[0020]
Here, when the image forming apparatus decrypts the data with the secret key, the data providing apparatus stores the public key corresponding to the secret key read by the reading unit of the image forming apparatus, and the key storage unit stores the public key. It is assumed that encryption means for encrypting data with the public key is provided, and the encrypted data is given to the image forming apparatus.
[0021]
Further, in a configuration in which the image forming apparatus includes a storage unit that stores a secret key, the data providing apparatus includes a first public key corresponding to a secret key read by the reading unit of the image forming apparatus, and a storage unit of the image forming apparatus. A key storage unit that stores a second public key corresponding to a stored secret key, and a cipher that encrypts data using the first public key and the second public key stored in the key storage unit An encryption unit is provided to provide the encrypted data to the image forming apparatus.
[0022]
Further, when the image forming apparatus decrypts the common key with the secret key and decrypts the data with the common key, the data providing apparatus stores the public key corresponding to the secret key read by the reading unit of the image forming apparatus. Means, a key generation means for generating a common key, and an encryption means for encrypting data with the common key generated by the key generation means and encrypting the common key with the public key stored in the key storage means Assume that the encrypted data and the encrypted common key are given to the image forming apparatus.
[0023]
Further, in a configuration in which the image forming apparatus includes a storage unit that stores a secret key, the data providing apparatus includes a first public key corresponding to a secret key read by the reading unit of the image forming apparatus, and a storage unit of the image forming apparatus. A key storage unit storing a second public key corresponding to the stored secret key, a key generation unit generating a common key, and encrypting data with the common key generated by the key generation unit, and a key storage unit Is provided with an encryption means for encrypting the common key with the first public key and the second public key stored in the memory, and the encrypted data and the encrypted common key are given to the image forming apparatus. .
[0024]
In these image forming systems, even if another device is interposed in the data transmission path from the data providing device to the image forming device, or the other device can access the transmission path, the confidentiality of the data is improved. Can be secured. Therefore, it is suitable for being part of a network system.
[0025]
In any of the image forming systems described above, the data providing device includes a data storage unit that stores the first data and a data generation unit that generates the second data, and the first data is encrypted by the encryption unit. And providing the encrypted first data and the generated second data to the image forming apparatus, and the image forming apparatus decrypts the first data by the decrypting means, and the image represented by the second data The image represented by the decrypted first data can be formed on the same sheet by the forming unit.
[0026]
In this way, when the image represented by the first data that should be kept confidential and the image represented by the second data that does not need to be kept secret are formed on the same sheet, management of those data is facilitated. Become. For example, when guaranteeing the contents of a document or form formed as an image on a sheet with a seal or signature as a second data for a document, a form, etc. The user can check the contents of the document or the form before the image is formed on the sheet.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image forming apparatus and an image forming system of the present invention will be described below with reference to the drawings. The configuration of the image forming system 1 according to the first embodiment and the data flow in the image forming system 1 are schematically shown in FIG. The image forming system 1 includes a server 10, a personal computer (PC) 20, and a printer 30. These are incorporated in a local network (LAN) connected by a cable (not shown) and set according to the Web system.
[0028]
The server 10 creates data representing an image to be printed (formed on a sheet). The personal computer 20 is directly operated by the user, instructs the server 10 to create data, receives data from the server 10, and transmits the data to the printer 30. The printer 30 forms data provided from the server 10 via the personal computer 20 as an image on a sheet.
[0029]
The personal computer 20 includes a web browser 21 that forms an interface with the server 10 and a display output system 22. A user who operates the personal computer 20 can log in to the server 10 via the Web browser 21, give a data creation instruction to the server 10, and receive the created data via the Web browser 21. Data received from the server 10 is given to the printer 30 from the display output system 22. The display output system 22 includes a display device (not shown), and a part of the data received from the server 10 can be displayed as an image by the display output system 22.
[0030]
The server 10 includes a web server 11, a business system 12, and a print data creation system 13. The Web server 11 serves as an interface with personal computers on the LAN such as the personal computer 20. The business system 12 manages the execution and control of various business operations including the generation of data to be printed. The user logs in to the business system 12 from the personal computer 20 via the Web browser 21 and the Web server 11, specifies the business to be performed, and gives necessary information.
[0031]
The print data creation system 13 is responsible for creating data to be printed, which is a part of the business performed by the business system 12. In response to an instruction from the user, the business system 12 gives data such as characters and numbers expressed in ASCII code to the print data creation system 13 as it is, and the print data creation system 13 receives the given data. Is expressed in PDL (page description language) suitable for printing. The data given from the business system 12 to the print data creation system 13 does not have to be particularly confidential.
[0032]
The business system 12 gives an instruction for creation together with the data to the print data creation system 13. This instruction includes an instruction to add other data that should be kept secret. Hereinafter, confidential data added by the print data creation system 13 is referred to as first data, and data provided from the business system 12 is referred to as second data. The print data creation system 13 includes a storage device and stores first data 16 in the storage device. The print data creation system 13 reads the first data 16 in response to an instruction from the business system 12 and stores the first data 16 together with the second data. 20 to send. The first data is expressed in PDL.
[0033]
In the image forming system 1, in order to ensure the confidentiality of the first data, the first data is encrypted by the server 10, transmitted to the printer 30 in an encrypted state, and decrypted by the printer 30. For this encrypted transmission, a public key method is adopted, encryption in the server 10 is performed using a public key, and decryption in the printer is performed using a secret key. In addition, encryption is performed twice, and a first secret key unique to the user and a second secret key unique to the printer 30 are used as a secret key for decryption.
[0034]
The business system 12 stores the first public key paired with the first secret key and the second public key paired with the second secret key. The business system 12 includes a storage device. The first public key and the second public key are stored in the storage device as the database 14 and read out according to an instruction from the user, together with the instruction and the second data. This is given to the print data creation system 13. The public key database 14 stores a user identification code and a printer code in association with the first public key and the second public key, respectively. The first public key and the second public key are selected according to the input identification code and the printer code given by the user together with the instruction.
[0035]
The print data creation system 13 includes an encryption module 15 and sequentially encrypts the first data 16 with the first public key and the second public key. When encrypting, either the first public key or the second public key may be used first.
[0036]
In the personal computer 20, among the first data and the second data provided from the server 10, the second data that is not encrypted can be displayed by the display output system 22. Thereby, the user can confirm the content of the 2nd data printed. The encrypted first data cannot be displayed. The first data and the second data can be stored in the display output system 22, but the first data can be displayed or printed even if the personal computer 20 can be accessed from another personal computer on the LAN. It cannot be acquired in a suitable form, and the confidentiality of the first data on the personal computer 20 is ensured.
[0037]
The printer 30 forms an interface with the personal computer 20 and also forms a printer engine 31 that forms an image represented by the given data on the sheet S and decrypts the first data to reproduce the first data before encryption. A decryption module 32 is provided. The printer engine 31 gives the first data of the first data and the second data given from the personal computer 20 to the decoding module 32 for decoding. Then, receiving the decrypted first data, the image represented by the first data and the image represented by the second data are formed on the same sheet S.
[0038]
The printer 30 includes a storage device, and stores therein a second secret key 33 unique to the printer 30. However, the printer 30 does not store the first secret key, and reads the first secret key as necessary. The first secret key is stored in a USB token 40 that is a storage medium that can be attached to and detached from the printer 30, and the printer 30 includes a USB connector 34 for mounting the USB token 40. The USB connector 34 is provided with a lamp (not shown) that indicates that the USB token 40 should be attached by lighting, and the decryption module 32 given the first data lights this lamp, The user is prompted to attach the USB token 40.
[0039]
In response to the lighting, the user attaches the USB token 40 storing the first secret key 41 to the USB connector 34, and the decryption module 32 reads the first secret key 41 from the USB token 40. Then, the decryption module 32 sequentially decrypts the doubly encrypted first data using the read first secret key 41 and the second secret key 33 read from the storage device. In this decryption, when the encryption module 15 of the server 10 performs encryption using the first public key first, the second secret key is used first, and the encryption module 15 performs the second public key. When encryption is performed using the key first, the first secret key is used first.
[0040]
After the decryption module 32 reads the first secret key 41, the user removes the USB token 40 from the USB connector 34 and manages it at his / her own risk. After decrypting the first data, the decryption module 32 immediately deletes the first secret key from its own memory regardless of whether the decryption succeeds or fails. This ensures that the first secret key is kept secret and the confidentiality of the first data on the printer 30 is ensured.
[0041]
A log storage device 50 is connected to the printer 30, and the printer engine 31 stores in the log storage device 50 the date and time when an image was formed on a sheet, the number of sheets on which an image was formed, the success or failure of image formation, and the like. In addition to the first secret key, the USB token 40 also stores information indicating the user. Each time the USB token 40 is attached to the USB connector 34, the information indicating the user is read by the decryption module 32. And stored in the log storage device 50 via the printer engine 31. Therefore, by looking at the stored contents of the log storage device 50, the user who has attached the correct USB token 40 to the USB connector 34 and the user who has attached the wrong USB token can be known.
[0042]
An organization such as a company or a public office provided with the image forming system 1 having such a configuration prints and issues data representing the seal or the signature of the responsible person in the server 10 as first data. It is possible to guarantee the contents of the document and reliably manage the data that should be kept confidential. Even when the printer 30 is a multi-function machine that also functions as a copying machine and a facsimile machine, data confidentiality management is easy and reliable.
[0043]
Processing for encrypting and decrypting the first data in the image forming system 1 is collectively shown in FIG. Encryption is performed in two stages. In the first stage, one of the first public key and the second public key (public key A) is used. In the second stage, the first public key and the second public key are used. The other one (public key B) is used. Decryption is also performed in two stages. In the first stage, the first secret key and the second secret key corresponding to the public key B (secret key B) are used. In the second stage, the first secret key is used. Of the key and the second secret key, the one corresponding to the public key A (secret key A) is used.
[0044]
The configuration of the image forming system 2 of the second embodiment and the data flow in the image forming system 2 are schematically shown in FIG. The image forming system 2 is different from the image forming system 1 of the first embodiment in encryption and decryption of the first data. Since there is no difference in other aspects, the same or similar components as those of the image forming system 1 are denoted by the same reference numerals, and redundant description is omitted.
[0045]
FIG. 4 shows the process of encrypting and decrypting the first data in the image forming system 2. The image forming system 2 employs a common key method for encryption and decryption of the first data. However, the common key is not stored in the printer 30 that performs decryption, but is encrypted from the server 10 that performs encryption and transmitted to the printer 30. The common key is encrypted twice using the two secret keys described in the first embodiment. Moreover, the common key is not stored in the server 10 but is generated in the server 10 every time it is encrypted.
[0046]
As shown in FIG. 3, the print data creation system 13 of the server 10 includes a common key generation module 17 from the business system 12, a creation instruction, second data, a first public key, and a first public key. When the public key 2 is given, the common key generation module 17 generates a common key. The common key generation module 17 generates an unspecified common key, for example, by generating a random number and using the random number. The encryption module 15 encrypts the first data 16 using the generated common key, and after the encryption, encrypts the common key sequentially with the first public key and the second public key. When encrypting, either the first public key or the second public key may be used first. The encryption module 15 erases the common key before encryption from its own memory immediately after encryption.
[0047]
The first data and the common key thus encrypted are transmitted to the personal computer 20 together with the second data, and are transmitted from the personal computer 20 to the printer 30. In the personal computer 20, among the first data and the second data provided from the server 10, the second data that is not encrypted can be displayed by the display output system 22. Thereby, the user can confirm the content of the 2nd data printed.
[0048]
The encrypted first data cannot be decrypted because the common key is encrypted, and therefore cannot be displayed. The first data, the second data, and the common key can be stored in the display output system 22, but even if another personal computer on the LAN can access the personal computer 20, the first data is not stored. It cannot be acquired in a form suitable for display or printing, and the common key cannot be acquired in a form suitable for decryption of the first data, and the confidentiality of the first data on the personal computer 20 is ensured. Is done.
[0049]
When the printer engine 31 of the printer 30 is given the first data, the second data, and the common key from the server 10 via the personal computer 20, the printer engine 31 gives the first data and the common key to the decryption module 32. The decryption module 32 stores the second secret key 41 that is double-encrypted with the first public key and the second public key and the first secret key 41 read from the USB token 40. The private key 33 is decrypted to reproduce the common key before encryption. Then, the first data is decrypted using the reproduced common key.
[0050]
When the common key is decrypted, when the encryption module 15 of the server 10 performs encryption using the first public key first, the second secret key is used first, and the encryption module 15 performs the second operation. When the encryption is performed using the public key first, the first secret key is used first. After the decryption of the first data, the decryption module 32 immediately deletes the common key and the first secret key from its own memory regardless of whether the decryption succeeds or fails. This ensures that the common key and the first secret key are kept secret, and the confidentiality of the first data on the printer 30 is ensured.
[0051]
In general, when the public key method and the common key method are compared, the calculation time required for processing, particularly the calculation time required for decryption, is about several hundred to several thousand times longer in the secret key method. In any method, the required calculation time becomes longer as the amount of data to be encrypted increases. In the image forming system 2 of the present embodiment, since the common key method is used for the encrypted transmission of the first data that tends to increase in volume, the processing from encryption to printing can be performed in a short time. Further, the image forming system 2 encrypts and transmits the common key, adopts a public key method for the encrypted transmission, and generates the common key every time encryption is performed. It is possible to ensure that the common key is kept secret. Therefore, ensuring the confidentiality of the first data is thorough.
[0052]
In each of the above-described embodiments, the case where the second data provided from the business system 12 to the print data creation system 13 does not need to be particularly confidential has been described. However, all or part of the second data is encrypted. Also in this case, the image forming systems 1 and 2 can be applied. In the first embodiment, the first data is encrypted twice. In the second embodiment, the common key is encrypted twice. However, the encryption is not necessarily performed twice. There is no need to do it seriously. In this case, however, the private key for decryption is preferably stored in a storage medium that can be attached to and detached from the printer. The removable storage medium for storing the secret key is not limited to the USB token 40, and other forms such as an IC card can also be used.
[0053]
The image forming systems 1 and 2 of the first and second embodiments are set according to the Web. However, it is not always necessary to set according to the Web, and the communication may be performed using a specific protocol. Absent. In that case, instead of the Web browser 21 or the Web server 11, a browser or server that matches the protocol may be provided. The image forming systems 1 and 2 include the personal computer 20. However, the personal computer 20 is omitted, or the server 10 is omitted by adding the functions of the server 10 to the personal computer 20. You can also. Furthermore, the present invention can be applied not only to the configuration of each embodiment in which the server 10 exists on the LAN but also to the configuration in which the server for creating data to be printed exists on the Internet.
[0054]
【The invention's effect】
In an image forming apparatus that receives encrypted data, decrypts the data, and forms an image represented by the decrypted data on a sheet. As in the present invention, the storage medium storing the secret key is attached to the secret key. Reading means for reading the data, decryption means for decrypting the data with the secret key read by the reading means given the data encrypted with the public key corresponding to the secret key, and data decrypted by the decryption means The image forming apparatus can be made to read the secret key used for decryption only when necessary, and the secret key for decryption can be surely kept secret. As a result, confidentiality of data is ensured.
[0055]
Further, the storage unit stores the secret key, and the decryption unit encrypts the data encrypted with the public key corresponding to the secret key read by the reading unit and the public key corresponding to the secret key stored by the storage unit When the data is decrypted with the secret key read by the reading means and the secret key stored in the storage means, the data is given to the image forming apparatus in a double-encrypted state. As a result, confidentiality is further enhanced.
[0056]
In an image forming apparatus that receives encrypted data, decrypts the data, and forms an image represented by the decrypted data on a sheet. As in the present invention, the storage medium storing the secret key is attached to the secret key. Reading means, data encrypted with the common key, and a common key encrypted with the public key corresponding to the secret key, and decrypting the common key with the secret key read by the reading means A decrypting means for decrypting data with the converted common key and a forming means for forming on the sheet an image represented by the data decrypted by the decrypting means. There is no need to store it in the apparatus, and the secret key for decrypting the common key can be read by the image forming apparatus only when necessary, and the confidentiality of the data is ensured. Further, since the data is decrypted with the common key, the time required for the decryption is short, and the formation of the image on the sheet can be started promptly.
[0057]
Furthermore, a storage means storing the secret key is provided, and the decryption means corresponds to the data encrypted with the common key, the public key corresponding to the secret key read by the reading means, and the secret key stored in the storage means Given the common key encrypted with the public key to be decrypted, decrypt the common key with the private key read by the reading means and the private key stored in the storage means, and decrypt the data with the decrypted common key In this case, the common key for decrypting the data is given to the image forming apparatus in a double-encrypted state, thereby further improving confidentiality.
[0058]
In the image forming system of the present invention constituted by the above image forming apparatus and a data providing apparatus for supplying data to the image forming apparatus, even if another apparatus is interposed in the data transmission path from the data providing apparatus to the image forming apparatus, or Even if other devices can access the transmission path, the confidentiality of the data can be ensured, so that it is suitable for being part of a network system.
[0059]
Here, the data providing device includes a data storage unit that stores the first data and a data generation unit that generates the second data, and the first data is encrypted by the encryption unit and encrypted. The first data and the generated second data are provided to the image forming apparatus, and the image forming apparatus decodes the first data by the decoding unit and decodes the image represented by the second data. When the image represented by the data is formed on the same sheet by the forming means, the image represented by the first data that should be kept confidential and the image represented by the second data that does not need to be kept confidential are placed on the same sheet. In the case of formation, management of those data becomes easy.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing the configuration and data flow of an image forming system according to a first embodiment.
FIG. 2 is a diagram schematically illustrating encryption and decryption processing of first data in the image forming system according to the first embodiment.
FIG. 3 is a block diagram schematically showing the configuration and data flow of an image forming system according to a second embodiment.
FIG. 4 is a diagram schematically illustrating processing for encrypting and decrypting first data in an image forming system according to a second embodiment.
[Explanation of symbols]
1, 2 Image forming system
10 servers
11 Web server
12 Business system
13 Print data creation system
14 Public key database
15 Encryption module
16 First data
17 Common key generation module
20 Personal computer
21 Web browser
22 Display output system
30 Printer
31 Printer engine
32 Decryption module
33 Second private key
34 USB connector
40 USB token
41 First private key
50 log storage

Claims (9)

Reading means attached to the storage medium storing the first secret key and reading the first secret key;
Storage means for storing a second secret key;
Given the information encrypted in two stages by the first public key corresponding to the first secret key and the second public key corresponding to the second secret key, the first secret key And decryption means for decrypting the information in two stages with the second secret key;
An image forming apparatus comprising: In an image forming apparatus that receives encrypted data and decrypts the data, and forms an image represented by the decrypted data on a sheet.
Reading means for reading the first secret key corresponding to the first public key by being mounted with a storage medium storing the secret key;
Storage means for storing a second secret key corresponding to the second public key;
Data encrypted in two stages is provided with a first public key corresponding to the first secret key read by the reading means and a second public key corresponding to the second secret key stored in the storage means Decrypting means for decrypting the data in two stages with the first secret key read by the reading means and the second secret key stored in the storage means;
Forming means for forming on the sheet an image represented by the data decrypted by the decrypting means
An image forming apparatus comprising: In an image forming apparatus that receives encrypted data and decrypts the data, and forms an image represented by the decrypted data on a sheet.
A reading means for reading the secret key by attaching a storage medium storing the secret key;
Given the data encrypted with the common key and the common key encrypted with the public key corresponding to the secret key, decrypt the common key with the secret key read by the reading means, and data with the decrypted common key Decoding means for decoding
An image forming apparatus comprising: a forming unit that forms an image represented by data decoded by a decoding unit on a sheet. A storage means for storing the secret key;
The decryption means uses the data encrypted with the common key, the public key corresponding to the secret key read by the reading means, and the common key encrypted with the public key corresponding to the secret key stored in the storage means. The decrypted common key is decrypted with the secret key read by the reading means and the secret key stored in the storage means, and the data is decrypted with the decrypted common key. Image forming apparatus. The image forming apparatus according to claim 1 and a data providing device for giving data to the image forming device.
The data providing device is
Key storage means for storing the first public key and the second public key;
Encryption means for encrypting information with the first public key and the second public key stored in the key storage means;
Providing encrypted information to the image forming apparatus
An image forming system. An image forming apparatus according to claim 2 and a data providing apparatus for giving data to the image forming apparatus.
Data provision device
A key storage unit storing a first public key corresponding to a secret key read by the reading unit of the image forming apparatus and a second public key corresponding to the secret key stored in the storage unit of the image forming apparatus;
An image forming system comprising: an encryption unit that encrypts data using the first public key and the second public key stored in the key storage unit, and providing the encrypted data to the image forming apparatus. system. An image forming apparatus according to claim 3 and a data providing apparatus for giving data to the image forming apparatus.
Data provision device
A key storage unit storing a public key corresponding to a secret key read by the reading unit of the image forming apparatus;
A key generation means for generating a common key;
The data is encrypted with the common key generated by the key generation means, and the encryption means for encrypting the common key with the public key stored in the key storage means includes the encrypted data and the encrypted common key as an image. An image forming system provided to a forming apparatus. An image forming apparatus according to claim 4 and a data providing apparatus for giving data to the image forming apparatus.
Data provision device
A key storage unit storing a first public key corresponding to a secret key read by the reading unit of the image forming apparatus and a second public key corresponding to the secret key stored in the storage unit of the image forming apparatus;
A key generation means for generating a common key;
Encryption is provided with encryption means for encrypting data with the common key generated by the key generation means and encrypting the common key with the first public key and the second public key stored in the key storage means And an encrypted common key are provided to the image forming apparatus. Data provision device
Data storage means for storing first data;
Data generating means for generating second data, the first data is encrypted by the encrypting means, and the encrypted first data and the generated second data are provided to the image forming apparatus;
The image forming apparatus decodes the first data by the decoding unit, and forms the image represented by the second data and the image represented by the decoded first data on the same sheet by the forming unit. The image forming system according to any one of claims 5 to 8.

Images