JP4337967B2 - Security network system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a network system composed of a PC, a printer, a facsimile, and the like. In order to maintain confidentiality, the image / document data encrypted by the PC is sent to a terminal such as a printer via the network and is output. Technology related to authentication, password authentication, and encryption / decryption.
[0002]
[Prior art]
In a network environment where a PC, a printer, or the like is connected, leakage of secrets is currently a problem. Image / document data existing on the network, such as information created on a PC connected to the network, file information, etc., is illegally output from multiple output devices such as printers connected to this, or stored in files etc. The information is leaked in various ways, such as the extraction of information, the hard disk of a personal computer, or theft of a personal computer. As a method of handling confidential information in order to avoid these problems, a method of encrypting and handling image / document data on a PC or a network and decrypting it when necessary is introduced. Various methods have been proposed for handling key information required for the encryption / decryption. There is also a known method for maintaining confidentiality by authenticating an individual with an ID, a password, etc., and making it impossible for anyone other than this individual to access information.
[0003]
A technique combining the key information and the personal authentication method is also introduced. As an example, JP-A-6-124178 is cited. FIG. 1 shows a system configuration of the present invention, and FIG. 2 shows a processing flow. The print data generation apparatus 1 includes an encrypted data generation unit A12 that encrypts print data and adds a user ID, a key code, and an encryption ID to the encrypted data and transfers the encrypted data to the printer. The printer has an encrypted data decrypting unit A23 that decrypts the encrypted data based on the ID or the like. The encrypted data transferred to the printer is temporarily stored in the spool queue A22. When printing, the encrypted data decrypting unit A23 decrypts and outputs only when the passwords match. Since only the encrypted data is stored in the spool queue A22, even if the contents are looked into, it is meaningless data to be seen, so the contents of the print data need not be known. That's it.
[0004]
Japanese Patent Laid-Open No. 2001-186358 combines a key in a card owned by a target receiver with a key held in the target image output device chip, and an encryption method, so that the target receiver is more reliable than the target image output device. A system that transmits images safely and generates them is introduced. This is the first private key / public key that controls the encryption of data for image generation. This private key is owned by the intended recipient, and the private key of the private key / public key is the target image output device. It is held and encrypted twice with these two keys. Therefore, in the case of decryption, it is necessary to decrypt the first key using these two secret keys.
[0005]
However, in Japanese Patent Laid-Open No. 2001-186358, when personal information is put in a device such as a card, it is impossible to prevent unauthorized use when it is lost or stolen. In order to prevent this, there is a method for specifying an individual by matching personal information and a password as disclosed in Japanese Patent Laid-Open No. 6-124178. In this case, the password may easily leak from the password input device and the network. There is a possibility that the data is also analyzed and leaked from the verification means stored inside the device for verification. In a network system, there must be no security weakness as described above.
[0006]
[Problems to be solved by the invention]
When encrypting / decrypting in order to prevent security leaks in a network system that handles image / document data, the key device is illegal after considering the relationship between the encryption / decryption key information, ID, and password. There is a need for means that does not have to worry about information leakage that covers the weaknesses of the system, such as usage, password leakage, and ID information leakage.
[0007]
[Means for Solving the Problems]
The invention of claim 1 is a terminal device that will be connected to the network system, the removable key device to the reading portion of the personal computer and printer having a reading unit, said key device, and computer functions, A power storage function, and the key device attached to the reading unit of the personal computer authenticates the password input from the personal computer to the key device by the computer function, and the authenticated password A password key is generated by a computer function, and an encryption / decryption key of image and document information is generated by the computer function using the generated password key, and after the generation of the encryption / decryption key, the key device The password in the computer A said key device annihilate in ability and the key device, until the password is eliminated from the input in the key device, when removed from the front Symbol reading unit, the electric storage function The password is extinguished by the computer function using the electric energy generated by , and the key device is initialized to a state before being attached to the reading unit.
The invention of claim 2 is a terminal device in a network system Ru is connected, includes a personal computer and a printer having a reading unit, and a key device detachable to said reading unit, said key device In a password authentication annihilation method in a network system attached to any reading unit of the terminal device, the key device has a computer function and a power storage function, and is attached to the reading unit of the personal computer, an authentication step of authenticating the path over coarsely braided password input from the computer to the key device of the computer functions, by the authenticated password authentication step, and the password key generation step of generating a password key by the computer functions, Generated in the generating step Encryption and decryption key generation steps for generating image and document information encryption and decryption keys with a password key, and after the encryption and decryption key generation, the password in the key device A password erasure step for erasing the password by the computer function, and when the key device is extracted from the reading unit between the time when the password is entered into the key device and the time when the password is annihilated. The password is deleted by the computer function using the electric energy generated by the power storage function, and the key device is initialized to a state before being attached to the terminal device.
According to a third aspect of the present invention, in the second aspect of the invention, the printer includes a button having a switch function that can be turned on and off, and a password can be input by turning the button on and off. Features.
In the present invention, in a network environment constituted by a management server, a network management device, a client PC (hereinafter referred to as a personal computer) printer, a fax, etc. connected to a network, after authentication by ID / password calculation / authentication means, An encryption / decryption key for image / document data is generated. These have a CPU and a memory and are put in an encrypted form in a key device having a computer function, and all terminal devices operated by humans are provided with a reader for this key device. To work on this network, first, a key device is inserted into the reader of the terminal device. The key device password is input from the keypad from the client PC. Next, the password is authenticated in the key device. The key device automatically locks when the password is continuously entered in a predetermined number of times. The authentication information in the key device is sent to the management server while being encrypted. The authentication information is previously encrypted with a basic key of the network management device. In the network server, authentication is performed in the server based on the basic key of the network management device and the authentication information registered in advance. Once authenticated, you can log in to the network.
[0008]
The password, using the 8-digit number as an example, becomes invalid when the input is incorrect 6 times, function key devices becomes impossible. When a password is input to the terminal, the password is sent to the key device attached to the terminal, and authentication is performed therein. Inside the key device, this password is in the form of a function that requires computation for verification. For example, the input password is x, the regular password x ₁ is an 8-digit positive integer, the number indicating how many times the filter is collated is n, and the password function is y = f (x, _n ) : Formula 1 is assumed. If the password x and the number of times n are determined, the value of the password function for each time is determined. The filter F performs matching at the a-th time and the b-th time, and Fa = f (x, n) −1: Formula 1 and Fb = f (x, n) +1: Formula 2 determines the filter value. To do. For example, if the filter F is configured such that Fa <y is satisfied at the second time and y <Fb is satisfied at the fifth time, y satisfies f, (x, n). become the only, x is recognized as _{x 1.} Since x ₁ is determined in advance, by decide whether to match in many times, the numerical value of each time the filter is determined. For example, the filters Fa and Fb are set for the second and fifth times. Other than this, a dummy filter Fd may be set. The dummy filter Fd is configured by 0 <Fd <f (x, n) −p: Formula 3 and f (x, n) + p <Fd <100000000: Formula 4. p is a positive integer of 1 or more. Password verification is performed by the above method. An example of verification is as follows. With y = 2nx and x ₁ = 12345678, the filter Fa is set at the second time, and Fb is set at the fifth time. The password function y is 2 × 2 × 12345678 = 49382712 for the second time, and the second filter Fa is 49382711 for 2 × 2 × 12345678-1, and the password function y for the fifth time is 2 × 5 × 12345678 = 123456780. The fifth filter Fb is 123456781. Fa = 49382711 in the second <positive integer satisfying y <Fb = 123456781 in 5th y without the addition _{x 1,} second and fifth filter Fa, the Fb, password _{x 1} is certified . F (x, n) can be a complex function within the range of CPU capability, and the number of times of the two collations can be arbitrarily set in combination with the dummy function. If x ₁ is authorized, the next step is to generate an encryption / decryption key of image / document data, and then delete x ₁ . If x entered at random does not match in the middle due to unauthorized use, the subsequent calculation is stopped, so it is difficult to determine the password x ₁ with 6 attacks even if the analysis is performed with an electrical signal. . It is also difficult to determine the password from the filter number including the dummy that remains in the key device memory. If the x ₁ has not been certified six times of attack, invalidation processing of the card is made. The above method of password verification is an example, and various methods other than the above method can be considered. If the analysis is difficult and it is difficult to determine the password, another method may be used.
[0009]
If the password is authenticated to enable the x _1, the password key that was based on it is issued. Extinguish x ₁ after generating an encryption / decryption key of the image / text data is the next step. An encryption / decryption key for the image and document data is generated by this password key and transferred to the PC to encrypt the image / document data. In the case of decoding by a terminal such as a client PC or a printer, the image / document data is decoded in the same procedure. Therefore, if the person who has the key device cannot input the password correctly, it cannot be encrypted / decrypted. An output device such as a printer is provided with a standard port such as USB or RS232C, a key device is inserted here, and a password is input to generate a decryption key in the same procedure as that of the client PC. / Decrypt document data and print it out. All communication data on the network is randomized by random numbers issued from the network management device. Since the present invention is a system in which confidentiality is not leaked in this way, confidentiality is maintained even if the network is of a large scale including public lines and satellite communications.
[0010]
For the encryption, an algorithm introduced as SXAL / MBAL, which is composed of, for example, a combination of exclusive OR, byte replacement, and substitution, and the processing unit is a variable length byte, is used. This makes it possible to create an encrypted image that is difficult to decipher at high speed. Other algorithms can be used if they are fast and difficult to decipher.
[0011]
Further explanation will be given for the case of outputting with the printer by the above procedure. Image information and document data are added with job information by the client PC, and are encrypted to become print data. The encrypted ID is added to this and sent to the printer. Information sent to the printer is stored in a storage device. The printer also has a key device reading device similar to that of the client PC. If the password input from the keypad is authenticated in the same procedure as described above, a password key is generated in the key device, and the decryption key is thus obtained. Generate and password disappears. The print data can be decrypted with the decryption key, and job information can be extracted and printed out. And ID of the output person in the image / document data encrypted at the same time as the printout, output date and time, can be made to the number are stored in the logging device of the printer. When performing printout, the client PC issues a printout instruction, and once the key device is removed, the key device is inserted into the key device reader of the network printer.
[0012]
The key device may be extracted from the reader at an abnormal timing, and in this case, it is necessary to erase the unnecessary information and normalize the key device at the moment of extraction. The operation at this time will be described. This operation is completed, for example, within 10 msec after being extracted, and this power is supplied from a capacitor such as a capacitor in the key device. As a result, the key device is initialized to the state before insertion into the reader. Next, even when it is inserted into the key device reader of the printer, the key device operates according to the procedure at the time of insertion. The key device is convenient for a small portable and detachable, and can also be composed of an IC card.
[0013]
As described above, by inserting the key device into a reader provided in the network terminal and inputting the password, password authentication, image / document data encryption / decryption, ID authentication, etc. can be performed. I can do it. If the password is not entered correctly, the information on the network cannot be encrypted or decrypted. Further, if the authentication information in the key device is not authenticated by the server, it cannot enter the network. Thereby, leakage of confidential information can be prevented. However, there is a risk of unauthorized use by a person other than the party due to loss or theft of this key device. Since a PC can input a password using a keyboard, unauthorized use can be prevented by combining the card and password input. However, terminal devices such as printers do not have a password input device. Many. However, the printer so as to have the logging function, ID of the output's can be made to be stored again been appended. As a result, the log information about who has what kind of information you did when output is to be stored in the internal printer. Output can ID decrypts the information, set the decryption key may be determined and level administrator with the key device. This system can increase the level of confidentiality. Does this administrator erase information stored in the printer? A method may be adopted in which old information is automatically deleted after a certain period of time or old information is deleted as much as new information is stored in a certain memory.
[0014]
Description will be given of a case to have the input device of the password to the printer. For this purpose, input keys on the numeric keypad may be provided, but space is required. Therefore, instead of the numeric keypad, a button or touch sensor having an ON / OFF function is provided, and a numerical value of several digits is spaced every digit. Enter and enter the password by pressing and holding . For example, if the input is 3, press it three times within 0.2 seconds and input the next numerical value at intervals of 0.5 seconds or more. According to this input , a password can be input with a simple device . The password is composed of 8-digit number, function of 6 times correctly entered unless the key device is made to be invalid.
[0015]
On the other hand, since the image / document data output from the printer is decrypted, it is touched by human eyes. For this reason, during output, it is impossible to leave the printer for security reasons. This is inefficient for time consuming outputs. As a means to solve this, a cover is provided on the paper output section of the printer, and there is a physical key on the cover, so that the cover can not be opened unless the card is inserted into the card reader of the printer. it is possible to prevent can also view the information. In this way, by inserting the key device to the printer, leave at the printer remove the key device by starting the printout, if to insert after the end key device again, to take out the print open the cover Will be able to .
[0016]
The information recorded in the memory of the logging function is recorded after being compressed, and in this case, in order to reduce the data capacity, an irreversible and reversible image compression method may be used as necessary. Good . For example, when a color image such as a picture and characters are mixed, the color image generally has a large amount of information, and the content can be grasped sufficiently even if it is irreversible. Therefore, a reversible compression method can be used. Also, not only the data to be stored but also all the data on the network are encrypted with a specific color (for example, black) or text, and other colors and images such as pictures and photos are treated as normal images. As a result, data reduction and high-speed processing can be performed .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail with reference to the drawings.
FIG. 3 shows an outline of a security network using a key device. In FIG. 3, 1 is a client PC, 2 is a printer, 3 is a logging device belonging to the printer, 4 is a server for managing the network, and 5 is a network. The devices connected to these networks have a key device reading means to which the key device 8 can be attached and detached as shown in the figure. 6 is a logging means belonging to the server 4 for managing the network, 7 is a network management device, 8 is a key device, which is composed of a CPU such as an IC card and a memory and has a computer function. You can also. Reference numeral 9 denotes a server display. The key device 8 includes personal authentication information such as an ID encrypted with a basic key of the server, password calculation, authentication function, and key generation means for encrypting / decrypting images and document data after password authentication. It is stored. The role of the key device is client PC, network login, user authentication, file / mail encryption / decryption, connection destination management, ID / password management for each APL, encryption log storage in printer 2 , Print output management, takeout of printout, management of availability of FD and the like. Without this key device, you cannot enter the network. Work in an encrypted network environment is possible by inserting a key device into a reader connected to a PC or a terminal device, or by inserting a key device into the reader.
[00018]
In addition, all information on the network is exchanged with each other in a state of being randomized by random numbers output from the network management device 7. The network management device 7 stores random number generation means, a basic key for encrypting personal information, and the like. This management device is physically protected, and its contents disappear when it is forcibly opened.
[0019]
FIG. 4 shows the procedure for encrypting image / document data from the PC and sending it to the printer. FIG. 5 shows the process for decrypting the encrypted image / document data received from the PC on the printer side, printing it out, and storing it in the logging function. The procedure of is shown. The key device has a password calculation and authentication function, and generates an encryption key for image / document data after authentication. After generating the encryption key, erase the password. On the other hand, the authentication information in the key device is sent to the server in an encrypted state, where it is authenticated and login to the network becomes possible. After the authentication, the client PC receives the encryption key of the image / document data from the key device, encrypts the image / document data, adds job information to this data, and randomizes it together with the encrypted ID and sends it to the printer. Since the printer also has a PC function, the procedure is the same as that of the PC described above, but the image / document data and the sender ID are stored in an encrypted form, and the time when the IC card is inserted is stored with the PC function. reading. The password is entered and verified in the key device in the same procedure as for the client PC. Also, the authentication information in the key device is sent to the server for authentication. The key necessary for decryption is obtained from the key device, and the image / document data is decrypted with this key and printed out. The printer has a logging function. When output to paper, the encrypted ID of the output person is appended to the document / image data that remains encrypted, and is stored together with the output date and time and the number of sheets. . It is also possible to select a document or image data stored in the printer, decode it, and print it out. The stored data can be output by a key device having a special authority key by an administrator having special authority. Although FIG. 6 has been described with reference to the means for solving the above-mentioned problem, a password input means using one button switch 10 is a cover for covering a printout portion with a key, and a key device is inserted by inserting a key device. Will open and the printout paper can be removed. When the key device is removed, it is closed and locked with the key. Further, the drawing shows the slit insertion port 12 when the reading of the key device is built in, but it is also possible to connect the reading device to the USB, RS232C terminal or the like of the printer.
[0020]
【The invention's effect】
By providing the same key device with a password authentication means as a means to prevent a non-authorized owner from using a key device that is convenient and effective for certifying individuals, the key device can be inserted and The encrypted data cannot be decrypted without entering the password. Since the password and the password authentication function are not left on the system side after the key device is removed, the password is not leaked from the system side as in the past. After use, the password disappears even within the key device, and the password authentication function is determined by a combination of multiple filters that limit the range of numerical values and the password function that changes according to the number of times. Since the key device is disabled by this attack, it is difficult to determine the password from the authentication means . In addition, there are also things that the printer does not have a numeric keypad for numeric input, using one of the buttons, one-touch sensor, ON, not take place because the input by the number of times of OFF, is valid.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration of JP-A-6-124178. FIG. 2 is a flowchart showing an operation procedure of JP-A-6-124178. FIG. 3 is a diagram showing an outline of a security network. Fig. 5 shows a procedure for encrypting image / document data. Fig. 5 shows a procedure for outputting an image sent from a client PC by a printer. Fig. 6 shows a key device insertion port and one button. Printer with cover for password input and output [Explanation of symbols]
A1 Print data generation device A2 Printer A11 Data print application A12 Encryption data generation unit A13 Encryption information storage unit A14 Magnetic disk A22 Spool queue A23 Encryption data decryption unit A24 Encryption decryption information storage unit A25 Key data processing unit A26 Magnetic disk A27 Print data Output unit 1 Client PC
2 Printer 3 Logging device belonging to printer 4 Network management server 5 Network 6 Logging device belonging to network management server 7 Network management device 8 IC card 9 Display for server 10 Input button 11 Cover 12 with key 12 Slit for key device

Claims (3)

Is a terminal device that will be connected to the network system, the removable key device to the reading portion of the personal computer and printer having a reading unit,
The key device has a computer function and a power storage function,
The key device attached to the reading unit of the personal computer is
Authenticates the password input from the personal computer to the key device with the computer function,
With this authenticated password, the computer function generates a password key,
With the generated password key, the computer function generates encryption and decryption keys for image and document information,
The key device for erasing the password in the key device with the computer function after generating the encryption and decryption keys; and
Said key device, until the password is eliminated from the input in the key device, when removed from the front Symbol reading unit, in the computer function by an electric energy by the energy storage function, disappearance of the password And the key device is initialized to a state before being attached to the reading unit. Is a terminal device that will be connected to a network system, a personal computer and a printer having a reading unit,
A key device detachable from the reading unit,
In a method for de-authentication of a password in a network system in which the key device is attached to any reading unit of the terminal device,
The key device has a computer function and a power storage function, and is attached to the reading unit of the personal computer.
An authentication step of authenticating the password entered into said key device from the path over coarsely braided computer of the computer functions,
A password key generating step of generating a password key with the computer function, using the password authenticated in the authentication step;
With the password key generated in the generating step, encryption of image and document information with the computer function, encryption for generating a decryption key, decryption key generation step,
A password extinction step of extinguishing the password in the key device with the computer function after generating the encryption and decryption keys;
It has, and,
When the key device is extracted from the reading unit between the time when the password is input into the key device and the time when it is deleted, the password is deleted by the computer function by the electric energy generated by the power storage function. And the key device is initialized to a state before being attached to the terminal device. In the password authentication cancellation method according to claim 2,
A password authentication extinguishing method, wherein the printer includes a button having a switch function that can be turned on and off, and a password can be input by turning the button on and off.

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