JP2006163956A - Security printing system, printer or multifunctional copying apparatus with printer function, ic card and information processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a security printing system, a printer or a multifunctional copying apparatus with a printer function which prevent information leakage in printing and can solve problems in system performance and cost, an IC card and a PC thereof. <P>SOLUTION: By a print instruction, secret printing password information is generated, and print data information to be transferred from a user PC1 to the printer 2 is encoded by a common key encryption algorithm. The user PC1 has a function for storing the secret print password information and key data for the common key encryption algorithm in a removable medium 3. The printer 2, by acquiring the secret print password information and the key data for the common key encryption algorithm from the removable medium 3, performs decoding processing for print data information in an encoded state stored in an HDD4, and only when a password information collation result shows a match, executes print processing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a security printing system, a printer or a multi-function copying apparatus having a printer function, an IC card, and an information processing apparatus, and in particular, security printing capable of preventing information leakage during printing and solving problems of system performance and cost. The present invention relates to a system, a printer, a multi-function copying apparatus having a printer function, an IC card, and an information processing apparatus.

A printer or a multifunctional copying machine (MFP) having a printer function is often used in a state where it is connected to a plurality of user PCs (Personal Computers) via a network. Since the printer is shared by a plurality of users, there is a high possibility that the printed matter that has been printed out will be in contact with the eyes of the person other than the person who issued the print instruction.
For this reason, various techniques for preventing information leakage during printing have been proposed. For example, as in Japanese Patent Application Laid-Open No. H11-228688, a user PC side that transmits print data adds password information (transfer password information) to the print data, and password information (separately input via a data input device provided on the printer side) ( There is a method in which the input password information) is compared by a password number collation unit inside the printer, and the printing process is executed only when they match.
In this method, password information is entered when the user issues a print instruction from the PC, or the password information generated by the PC is displayed on the monitor. The print data to which the password information is added is transferred to the printer via the network, but printing is not performed after the transfer is completed. The user who has instructed printing moves to the place where the printer is placed, inputs the password information from the data input device, and printing is performed only after the match with the transferred password information is confirmed. Since the printed matter is not printed out unless the personal identification information is leaked, the secret document can be prevented from touching others. This function is often called confidential printing or confidential printing.
The technique of Patent Document 2 encrypts the print data on the printer side, and stores the encrypted print data without printing out until the print instruction user authentication process is completed. Separately, it is described in the specification that the print data on the network is encrypted by a secure communication protocol such as SSL or TLS, and the print data stored on the network and in the HDD in the printer leaks information by encryption. Protected against threats.

The technique of Patent Document 3 is a technique that uses the technique used for e-mail encryption for confidential printing, generates a disposable key (session key) for each print data, and stores the session key together with the print data in the printer. The transfer method is adopted. Since this method does not require a PKI (public key infrastructure), development cost / introduction cost can be suppressed as compared with SSL or TLS.
As another technology, a technology related to confidential printing of a product named “Ridoc PrintShield” that performs security management of printing information at the time of printing uses authentication by an IC card used on a user PC instead of password information. Yes. When the IC card is inserted into the IC card reader connected via the printer main body or the interface, the personal authentication is performed and the printing process is performed. If there is no printed IC card of the principal, the print data remains stored in the data storage means in the printer, so that information leakage due to printed matter can be prevented.
The technique of Patent Document 4 is configured to determine whether printing is possible based on the presence or absence of printed identification information extracted from print image data, and the printed identification information is generated from a hash function. As a result, when printing securities such as bills and checks from the securities inquiry server via the network via the network, it is possible to conduct fraudulent acts such as leakage of data stored in the securities image, falsification, duplication of printed securities, tampering, etc. It can be prevented.
JP-A-9-218757 JP 2001-188664 A JP 2001-306273 A JP 2003-237186 A

However, in the method of Patent Document 1, there is a threat that the printed material is intercepted and confidential information is leaked when the keyboard input or the monitor screen output at the time of printing instruction is observed or obtained by leakage electromagnetic wave analysis. There is also a threat that the password information is illegally acquired via the network because the transferred password information flows on the network. In the present invention, there is no mention of encryption processing of communication data flowing on the network and data temporarily stored in the HDD in the printer, and not only the transfer password information but also the print data itself from the network or the HDD in the printer. There are extremely dangerous threats of unauthorized acquisition.
The above-described method in PrintShield has the following problems. One is that the data on the network and the data stored in the HDD are separately encrypted, and a plaintext state appears when decryption is performed before the data is stored in the HDD. There is a threat that this plaintext state is illegally acquired by some method. Further, in order to perform encryption of network communication data, it is necessary to implement a secure communication protocol such as SSL or TLS, which increases costs on the system development side and system introduction side.
In the case of the technique disclosed in Patent Document 2, authentication using public key encryption and encrypted communication processing are necessary. Since public key cryptography has an extremely slow processing speed compared to the common key cryptosystem, problems such as performance degradation of the printing system via the network cannot be avoided.
In the method of Patent Document 3, authentication via a network is performed using personal authentication data stored in an IC card, and the data used for authentication is always the same. Therefore, there is a threat that authentication data is acquired by traffic analysis on the network and personal authentication data is forged. In this case, it is conceivable that a third party other than the person illegally obtains the printed material by using the counterfeit IC card, or other illegal acts by impersonation are performed.
Further, in the technique of Patent Document 4, the use method of the generated data is used only for determining whether or not the printing has been performed. Therefore, the application is limited and security management for general printing operations cannot be handled. .
Therefore, the present invention has been made in consideration of the above-described actual circumstances, and includes a security printing system, a printer, or a printer function that can prevent information leakage at the time of printing and solve problems of system performance and cost. An object of the present invention is to provide a multi-function copying apparatus, an IC card, and an information processing apparatus.

In order to solve the above-described problem, the invention according to claim 1 is configured such that a user information processing apparatus and a printer or a multi-function copying apparatus having a printer function are connected via a network, and print data information is received from the user information processing apparatus. In a security printing system that transfers to the printer or the multi-function copying apparatus and performs a printing process based on the print data information, secret print password information is generated by a user's print instruction, and the printer or The print data information transferred to the multi-function copying apparatus is encrypted by a common key encryption algorithm, and the user information processing apparatus stores the confidential print password information and the key data of the common key encryption algorithm in a removable medium. Storage means, the printer or the multi-function copying apparatus Data storage means capable of storing the print data information transferred from the user information processing apparatus, and the encrypted print state by obtaining the secret print password information of the removable medium and the key data of the common key encryption algorithm The printing data information stored in the data storage means is decrypted, and the printing process is executed when the password information matching results match.
According to a second aspect of the present invention, the removable media is mainly characterized by a security printing system in which the removable medium is a USB memory, a compact flash (registered trademark) card or an SD card.
According to a third aspect of the present invention, a security printing system that uses an IC card instead of the removable medium is a main feature.
According to a fourth aspect of the present invention, there is provided a security printing system in which the secret print code information and the key data of the common key encryption algorithm are one-time disposable data corresponding to specific print data information. And
According to a fifth aspect of the present invention, there is provided a security printing system in which the print data information in the data storage unit is automatically deleted when the print data information transferred from the user PC is not subjected to printing processing within a predetermined time. Main features.

According to a sixth aspect of the present invention, in the security printing system according to the fifth aspect, a notice is displayed on the user information processing apparatus screen that the print data information of the data storage unit is automatically deleted. And
According to a seventh aspect of the present invention, there is provided a printer or a multi-function copying apparatus having a printer function that is connected to a user information processing apparatus through a network and performs print processing based on print data information transferred from the user information processing apparatus. And a data storage unit capable of storing the print data information transferred from the user information processing apparatus from a part of the print data information by a one-way function, and an IC card Alternatively, the information of the removable medium can be read.
According to another aspect of the present invention, a user information processing apparatus and a multi-function copying apparatus having a printer or a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multi-function copying apparatus. When transferring to the apparatus and performing print processing based on the print data information, a part of the print data information is obtained from the user information processing apparatus, and a part of the print data information is obtained by a one-way function. Means for generating constant byte length data is provided.
According to a ninth aspect of the present invention, a user information processing apparatus and a multi-function copying apparatus having a printer or a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multi-function copying apparatus. When the print data is transferred to the apparatus and print processing is performed based on the print data information, constant byte length data is generated from a part of the print data information by a one-way function.
According to a tenth aspect of the present invention, in the printer or the multi-function copying apparatus having the printer function according to the seventh aspect, a hash value input from the IC card or the removable medium and a hash value generated internally are provided. Comparing means for comparing the data is provided.
According to an eleventh aspect of the present invention, in the printer according to the tenth aspect or the multi-function copying apparatus having a printer function, the print data information transferred from the user information processing apparatus is stored in a data storage unit. When the results of the data comparison are the same, a printing process is performed, and the printing data information in the data storage unit is erased after the printing process is completed.

According to a twelfth aspect of the present invention, the printer includes the printer according to the eleventh aspect or a multi-function copying apparatus having a printer function, an IC card according to the eighth aspect, and an information processing apparatus according to the ninth aspect. .
According to a thirteenth aspect of the present invention, a user information processing apparatus and a multifunctional copying apparatus having a printer or a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multifunctional copying apparatus. When transferring to the apparatus and performing print processing based on the print data information, a part of the print data information is obtained from the user information processing apparatus, and a part of the print data information is obtained by a one-way function. A security printing system comprising: a removable medium having a function of generating constant byte length data; a printer according to claim 11; a multi-function copying apparatus having a printer function; and an information processing apparatus according to claim 9. Media can be USB memory, Compact Flash (registered trademark) card or Characterized in that it is a SD card.
According to a fourteenth aspect of the present invention, in the printer or the multi-function copying apparatus having the printer function according to the seventh aspect, the one-way function includes MD2, MD4, MD5, SHA-1, SHA-256, One of SHA-384 and SHA-512 is used.
In the invention according to claim 15, in the IC card according to claim 8, any one of MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512 is included in the one-way function. It is characterized by using or.
In the invention according to claim 16, in the information processing device according to claim 9, the one-way function includes MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512. Any one of them is used.
According to a seventeenth aspect of the present invention, there is provided a security printing system using the printer according to the seventh aspect, a multi-function copying apparatus having a printer function, an IC card according to the eighth aspect, or an information processing apparatus according to the ninth aspect. The print data information used for generating the hash value includes at least print data information generation time information in the user information processing apparatus.
According to an eighteenth aspect of the present invention, in the printer or the multi-function copying apparatus having the printer function according to the seventh, tenth, or eleventh aspect, the print data information transferred from the user information processing apparatus is a predetermined time. The print data information of the data storage means is automatically deleted when the print processing is not performed within the range.
According to a nineteenth aspect of the present invention, the fact that the print data information of the data storage means in the printer or the multi-function copying apparatus having a printer function according to the eighteenth aspect is automatically deleted is displayed on the user information processing apparatus screen. A notice is displayed on the screen.

According to the present invention, the system configuration is such that the print instructor delivers the key data used for encrypting the print data information and the password information used for confidential printing from the user PC to the printer via the removable medium or the IC card. Therefore, an encrypted confidential printing system that does not require a key distribution protocol using public key cryptography and a public key infrastructure (PKI) can be configured. It is possible to solve the problem of system performance and cost due to the necessity of public key cryptography with a slow processing speed.
In addition, since the key data used for encrypting the print data information has a system configuration that does not pass through the network, the key data itself is a one-time disposable item corresponding to specific print data. It is possible to configure an encrypted confidential printing system with a low threat of information leakage by illegally acquiring or analyzing data.
Also, in confidential printing, if print processing is not executed even after a certain period of time, the print data information stored in the HDD of the printer is erased, so that an HDD that can occur when the print instructor forgets the print processing Information leakage due to unauthorized access to internal data can be prevented. In addition, since an advance notice is given to the print instructor before the print data information is automatically erased, it is possible to reduce human load / system load due to reprint processing.

In addition, since the hash value obtained as a result of inputting information unique to the print data information to the hash function is used as the secret information in the confidential printing, confidential printing with high security strength can be realized without duplication of the secret information.
In addition, the personal identification information for confidential printing is delivered from the user PC to the printer via a removable medium or IC card. Since no leakage occurs, it is possible to realize confidential printing with high security strength so that the printed material is not seen by a third party.
Also, in confidential printing, if print processing is not executed even after a certain period of time, the print data information stored in the HDD of the printer is erased, so that an HDD that can occur when the print instructor forgets the print processing Information leakage due to unauthorized access to data in the network can be prevented. In addition, since an advance notice is given to the print instructor before the print data information is automatically erased, it is possible to reduce human load / system load due to reprint processing.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings. Here, seven embodiments are shown as the best mode for carrying out the present invention. First, the security printing system according to the first to fourth embodiments will be described, and then the security printing system and the printer according to the fifth to seventh embodiments. Alternatively, a multi-function copying apparatus, IC card, and information processing apparatus having a printer function will be described. The printer shown as the printing means in the description of the first to seventh embodiments may be a multi-function copying apparatus having a printer function.
In the first to fourth embodiments, the greatest feature of the security printing system is that in confidential printing, print data information is encrypted on the user PC (Personal Computer) side, and the encrypted print data information is left as it is on the printer side. Is temporarily stored in the HDD (Hard Disk Drive) in the printer status, and the key data used for encryption is delivered via the removable media or IC card via the removable media or IC card, without the network. It is to be.

As shown in FIG. 1, the security printing system according to the first embodiment includes a PC (hereinafter referred to as a user PC) 1 and a printer 2, which are connected to a network. The user PC 1 has a function of encrypting print data information using a common key encryption algorithm and a function of generating confidential print code information corresponding to a print job. The printer 2 includes an HDD 4 as a data storage unit that can temporarily store print data information, a function for decrypting the encrypted print data information, and an interface for the removable medium 3.
When the user issues a print instruction on the printer driver GUI screen, as shown in FIG. 2, print job information (for example, job ID / paper size / print direction / print data generation time) for print data is displayed inside the user PC 1 as shown in FIG. The “print data information” 12 is generated to which the header 10 and the data end ID 11 indicating the end of the print data information are added.
This “print data information” 12 is encrypted by a common key encryption algorithm provided in the PC. However, since it is necessary to identify the job ID before decryption on the printer side, at least the job ID in the header 10 is to be encrypted. Need to be excluded (see FIG. 3). The “encrypted print data information” 13 is transferred to the printer via the network, and the “encrypted print data information” 13 is stored in the HDD 4.
Examples of the common key encryption algorithm include AES, DES, Triple-DES, RC4, and the like, but it is desirable in terms of security to use a standard encryption algorithm selected by the Japanese CRYPTREC activity or the European NESSIE project.

The confidential print password information for identifying the print job is generated from a random number or “print data information”, and is written in the removable medium 3 together with the key data used for encryption. As the removable medium 3, for example, a USB memory, a compact flash (registered trademark) card, an SD card, or the like can be used.
The user who issued the print instruction removes the removable medium 3 from the user PC 1, moves to the place where the printer 2 to which the print data information has been transferred, and inserts the removable medium 3 into the reading device of the printer 2. The printer 2 reads the confidential print code information and the key data from the stored data of the removable medium 3, and identifies the print data information transferred from the user PC 1 by the confidential print code information.
The confidential print code information may be included in “encrypted print data information” stored in the HDD 4, or the printer uses the same method as the user PC after decrypting the “encrypted print data information”. 2 may be generated inside. Confidential print code information obtained from the removable media 3 is checked against the “encrypted print data information” or the confidential print code information generated inside the printer 2. If they match, the common key obtained from the removable medium 3 is used. The print data decoding is performed, and the printing process is executed.
The main features of this method are that the encryption key used for encrypting and decrypting the print data is one-time use, and there is no need to distribute the key data via the network. When the same key is used continuously in data encryption, it is known that there is a high risk that a malicious third party will be decrypted by acquiring a plurality of encrypted data.
Since the security printing system according to the present invention uses a one-time key for one piece of print data, the above risk can be avoided. In addition, since the user himself / herself who has printed using removable media delivers key data, it is not necessary to construct a key distribution protocol that uses public key cryptography and a public key infrastructure (PKI) that is necessary for using public key cryptography. Thereby, the development cost / introduction cost for realizing the encrypted confidential printing can be significantly reduced.

  As shown in FIG. 4, an IC card 5 on which a CPU is mounted may be used instead of the removable medium 3 in the first embodiment. In this case, the secret print code information is generated on the IC card 5 side. Advantages that high security strength can be obtained compared to the first embodiment because the confidential printing PIN information does not remain on the PC and the tamper resistance of the IC card 5 makes it difficult to illegally analyze the generation of the confidential printing PIN information. There is.

It is also possible to share the secret print password information and the encryption key. For example, on the user PC 1 side, a CRC (Cyclic Redundancy Check) calculated from all or part of the “print data information” is added, and at least the “print data information” excluding the job ID is encrypted using a common key encryption algorithm. (See FIG. 5).
The “print data information” is decrypted by using the encryption key (= confidential print password information) acquired from the removable medium 3 or the IC card 5 inserted into the printer 2 by the user. A CRC is calculated from the decoded data, and printing processing is executed when a correct result is obtained. Alternatively, it is determined whether the correct encryption key (= confidential print password information) is obtained by adding fixed value information to the “print data information” and decrypting on the printer 2 side. It is also possible to do this.

This example has a function of erasing the print data in the HDD 4 when the print data transferred from the user PC 1 is not subjected to print processing within a certain time. In this case, the security strength can be further increased. In the encrypted confidential printing, the print data information in the HDD 4 is held in an encrypted state for a period until the user who gives the print instruction inputs the confidential printing password information.
For this reason, if the user who issued the print instruction forgets to print out, the print data information remains stored in the HDD 4. Although the security risk is much lower than when the stored data is stored in a plain text state, it is not preferable to leave the data in the HDD 4 for a long time.
In the fourth embodiment, a counter mechanism that measures the elapsed time based on the time when the print data transferred from the user PC is stored in the HDD 4 is provided, and the print data is automatically deleted when a certain time has passed. Yes. Although it is desirable that the automatic erasure time can be variably set, it is necessary to deal with a plurality of confidential print jobs. Considering hardware or software resources, the maximum setting value is about 1 hour. In addition, if software that issues a message to notify automatic erasure is installed on the screen of the user PC 1 that has instructed printing, it is possible to reduce the human load / system load due to reprint processing.
As described above, in the security printing system of the above-described embodiment, the print instructor uses the removable medium 3 or the IC card 5 to print the key data used for encrypting the print data information and the secret information used for confidential printing. Since the system is configured to deliver from the PC to the printer, it is possible to configure an encrypted confidential printing system that does not require a key distribution protocol using public key cryptography and a public key infrastructure (PKI). It is possible to solve the problem of system performance and cost due to the necessity of public key cryptography with a slow processing speed.
In addition, since the key data used for encrypting the print data information has a system configuration that does not pass through the network, the key data itself is a one-time disposable item corresponding to specific print data. It is possible to configure an encrypted confidential printing system with a low threat of information leakage by illegally acquiring or analyzing data.
Further, in the case of confidential printing, the print data information stored in the HDD 4 of the printer 2 is erased when the print process is not executed even after a predetermined time has elapsed. This can occur when the print instructor forgets the print process. Information leakage due to unauthorized access to data in the HDD 4 can be prevented. In addition, since an advance notice is given to the print instructor before the print data information is automatically erased, it is possible to reduce human load / system load due to reprint processing.

Next, in Examples 5 to 7, a security printing system, a printer or a multi-function copying apparatus having a printer function, an IC card, and a PC, which are the best modes for carrying out the present invention, will be described. The greatest features of the fifth to seventh embodiments are that a hash function is used to generate password information in confidential printing, and that the password information is not transferred to the printer via the network, thereby realizing a printing system with high security strength. is there.
The hash function is a function that converts arbitrary bit length data (the upper limit is a bit length that can be input) into fixed bit length data (usually about 128 to 512 bits), and for purposes such as password authentication / digital signature / message authentication. It is widely used and constitutes an important field of modern cryptography as well as a pseudo-random number generator. One of the most important characteristics when using a hash function in cryptographic technology is unidirectionality and collision difficulty.
The “one-way hash function” is a hash function that is “difficult in calculation” to obtain an original value x such that h (x) = y from the function value y. The collision-resistant hash function is a hash function in which it is difficult to obtain a pair of values (x, z) such that h (x) = h (z) when the function h is given (see FIG. 6).

The reason why the hash function is used for generating the password information in the present invention is the collision difficulty of the hash function. It is said that the output data (hash value) changes greatly only when the data input to the hash function is different by 1 bit, and the probability that the same output data (hash value) is generated from different input values is said to be extremely low. For this reason, even when the same print data is printed, if the header information added before and after the print data is different, a completely different hash value is obtained.
For example, print data output date / time and time are generally added to the second unit as header information. If print data information (header information + print data) including at least this information is used for the input of the hash function, The hash value obtained by the hash function process can be regarded as random data without duplication. Since the personal identification information used for the confidential printing process needs to be random data without duplication, the hash value generated by the above method can be used as the personal identification information for the confidential printing.
Although it is conceivable to use a pseudo-random number generator for generating random data, the pseudo-random number generator has a risk of appearing secret information of the same data unless attention is paid to the method selection and mounting method. For example, when the pseudo-random number generator is reset in hardware or software and returns to the initial state, there is a risk of outputting the same data series as after the previous reset.
The security threat when transferring the password information to the printer via the network is as described in the object of the invention. In the present invention, confidential printing can be realized without transferring the personal identification information to the printer via the network by the two types of methods shown in the following embodiments.

In the fifth embodiment, a method for generating hash values inside the user PC 1a will be described (see FIG. 7). When the user issues a print instruction on the printer driver GUI screen, a header and print data information indicating print job information (for example, job ID / paper size / print direction / print data generation time) for the print data in the user PC 1a. “Print data information” (see FIG. 8) to which a data end ID indicating the end of the data is added is generated, and this “print data information” is transferred to the printer 2a via the network. “Print data information” is stored in the HDD 4.
In the conventional technology of the printer, the secret print secret information is included in the “print data information” and flows on the network. In this embodiment, a part of the “print data information” is extracted, and the hash value generated by the hash value generation function provided in the user PC 1a becomes the secret print secret information. The hash value generated inside the PC is hereinafter referred to as hash value A.
Examples of the hash function algorithm used include MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512. The hash value generation function may be implemented by either hardware or software, but is preferably implemented by software in consideration of setting a plurality of hash functions to be used. Specifically, it is implemented by a printer driver. Is considered optimal.

The secret print secret information (hash value) generated inside the user PC 1a is written to the removable medium 3a together with the print job number. As the removable medium 3a, a USB memory, a compact flash, an SD card, or the like can be used.
The user who issued the print instruction removes the removable medium 3a from the user PC 1a, moves to the place where the printer 2a to which the print data information is transferred, and inserts the removable medium 3a into the reading device of the printer 2a. The printer 2a reads the print job number and the hash value A from the stored data of the removable medium 3a, and identifies the print data information transferred from the user PC 1a by the print job number.
The printer 2a has a function of generating fixed byte length data (hash value) from a part of print data information by a one-way function (hash function), and the same hash function as the same print data information as the user PC 1a. An algorithm is used to generate a hash value. A hash value generated inside the printer 2a is referred to as a hash value B.
For the input data of the hash function, for example, header information including a print job number and print data transmission time information and a part of the print data are used. The number of input data bytes may be a constant value regardless of the print data, or may be changed for each print data. When changing for each print data, it is necessary to embed information indicating the hash function input range in the header portion of the transferred print data information.
The printer 2a has a function of comparing the hash value A input from the removable medium 3a with the internally generated hash value B. If the hash value A and the hash value B are the same, a print instruction is issued. Since the user himself / herself can be determined to be the same person as the person who inserted the removable medium 3a, printing processing of print data corresponding to the print job stored in the HDD 4 is started.
In the above confidential printing method, the secret printing secret information is input to the printer 2a via the removable medium 3a and does not pass through the network, so that it is illegally acquired on the network to be touched by a third party. It cannot happen. In addition, since the secret print secret information is generated by using a value obtained by inputting information unique to the print data information to the hash function, a unique value is used for each print job. With these two features, confidential printing that solves the problems of the prior art can be realized.

In the sixth embodiment, a case where hash value generation is performed inside the IC card will be described (see FIG. 9). The IC card 5a has a function of acquiring a part of print data information from the user PC 1b and generating constant byte length data (hash value) by a one-way function (hash function), and issues a print instruction on the user PC 1b. When performing, the data necessary for generating the secret print password information (hash value A) is transferred to the memory area in the IC card 5a. The difference from the fifth embodiment is that the hash value A is generated not in the user PC 1b but in the IC card 5a. Since other operations are the same as those in the fifth embodiment, detailed description thereof is omitted.
As an advantage of the method of generating the hash value inside the IC card 5a, since the hash value does not remain on the user PC 1b and the illegal analysis of the hash value generation algorithm becomes difficult, the security is higher than that of the fifth embodiment. The strength can be obtained.

If the print data transferred from the user PC is not subjected to print processing within a certain time, the security strength can be further increased by providing a function for erasing the print data in the data storage means (HDD). The print data information in the data storage means (HDD) is retained until the user who gives the print instruction inputs the secret print secret information. If the user who gives the print instruction forgets the printout, the printout is performed. Data information remains stored in the data storage means (HDD), and is exposed to an information leakage threat due to unauthorized access to the HDD.
In this example, a counter mechanism is provided for measuring the elapsed time based on the time when the print data transferred from the user PC is stored in the data storage means (HDD), and the print data is automatically deleted when a certain time has elapsed. It is like that. Although it is desirable that the automatic erasure time can be variably set, it is necessary to deal with a plurality of confidential print jobs, and considering the hardware or software resources, it is appropriate that the maximum set value is about 1 hour. In addition, if software that issues a message to notify automatic erasure is installed on the user PC screen instructed to print, it is possible to reduce human load / system load due to reprint processing.
As described above, in the security printing system, the printer or the multi-function copying apparatus having the printer function, the IC card, and the information processing apparatus according to the fifth to seventh embodiments, the result obtained by inputting information unique to the print data information to the hash function is obtained. Since the hash value is used for personal identification information in confidential printing, confidential printing with high security strength without duplication of personal identification information can be realized.
The secret information in the confidential printing is delivered by the print instructor from the user PC 1a to the printer 2a via the removable medium 3a or the IC card 5a. Therefore, the confidential printing is performed by illegally acquiring network data or snooping on the monitor screen of the user PC 1a. Since there is no leakage of personal identification information, it is possible to realize confidential printing with high security strength so that the printed matter is not seen by a third party.
Further, in the case of confidential printing, the print data information stored in the HDD 4 of the printer 2a is erased when the printing process is not executed even after a certain time has elapsed, so that this may occur when the print instructor forgets the printing process. Information leakage due to unauthorized access to data in the HDD 4 can be prevented. In addition, since an advance notice is given to the print instructor before the print data information is automatically erased, it is possible to reduce human load / system load due to reprint processing.

  In this description, the secret print code information is generated by the user's print instruction, the print data information transferred from the user PC to the printer is encrypted by the common key encryption algorithm, and the user PC is shared with the secret print code information. The key data of the key encryption algorithm is stored in the removable medium, and the printer obtains the secret print secret information of the removable medium and the key data of the common key encryption algorithm, and stores them in the data storage means (HDD) in an encrypted state. And a one-way function based on a part of the print data information, in which the print data information is decrypted and the print processing is executed only when the personal identification information collation results match. (Hash function) generates fixed byte length data (hash value) and stores information specific to print data information. Having described the hash value obtained as a result of the input to the Mesh function individually technology (Examples 5-7) as adapted to use the personal identification information in the security printing, these techniques may be those complexes. In this case, the above-described effects can be obtained at the same time.

1 is a schematic configuration diagram of a security printing system in Embodiment 1. FIG. FIG. 3 is a schematic diagram (part 1) illustrating a configuration of print data information. FIG. 6 is a schematic diagram (part 2) illustrating a configuration of print data information. It is a schematic block diagram of the security printing system in Example 2. FIG. FIG. 6 is a schematic diagram (part 3) illustrating a configuration of print data information. It is explanatory drawing of a one-way hash function. FIG. 10 is a schematic configuration diagram of a security printing system according to a fifth embodiment. FIG. 6 is a schematic diagram (part 4) illustrating a configuration of print data information. FIG. 10 is a schematic configuration diagram of a security printing system according to a sixth embodiment.

Explanation of symbols

1, 1a, 1b User PC
2, 2a Printer 3, 3a Removable media 4 HDD
5, 5a IC card

Claims (19)

A user information processing apparatus and a printer or a multifunction copying apparatus having a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multifunction copying apparatus, and the print data information In a security printing system that performs printing processing based on
Generating secret print code information according to a user's print instruction, encrypting the print data information transferred from the user PC to the printer or the multi-function copying apparatus using a common key encryption algorithm;
The user information processing apparatus includes storage means for storing the secret printing code information and key data of the common key encryption algorithm in a removable medium,
The printer or the multi-function copying apparatus includes a data storage unit capable of storing the print data information transferred from the user information processing apparatus, and stores the confidential print password information of the removable medium and key data of the common key encryption algorithm. By acquiring the encrypted data, the print data information stored in the data storage unit is decrypted, and the print processing is executed when the password information matching results match. Printing system. The security printing system according to claim 1,
The security printing system, wherein the removable medium is a USB memory, a compact flash (registered trademark) card or an SD card. The security printing system according to claim 1,
A security printing system using an IC card instead of the removable medium. The security printing system according to claim 1,
The security printing system, wherein the secret print password information and the key data of the common key encryption algorithm are one-time disposable data corresponding to specific print data information. The security printing system according to any one of claims 1 to 4,
The security printing system according to claim 1, wherein when the print data information transferred from the user PC is not subjected to a printing process within a predetermined time, the print data information in the data storage unit is automatically deleted. The security printing system according to claim 5, wherein
A security printing system for displaying a notice on the screen of the user information processing apparatus that the print data information of the data storage means is automatically deleted. In a multi-function copying apparatus that is connected to a user information processing apparatus via a network and that performs a printing process based on print data information transferred from the user information processing apparatus or has a printer function,
A means for generating a fixed byte length data from a part of the print data information by a one-way function; and a data storage means for storing the print data information transferred from the user information processing apparatus. A multi-function copying apparatus having a printer or printer function characterized in that it can read media information. A user information processing apparatus and a printer or a multifunction copying apparatus having a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multifunction copying apparatus, and the print data information When performing print processing based on
An IC card comprising means for acquiring a part of the print data information from the user information processing apparatus and generating a fixed byte length data from the part of the print data information by a one-way function. A user information processing apparatus and a printer or a multifunction copying apparatus having a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multifunction copying apparatus, and the print data information When performing print processing based on
An information processing apparatus for generating fixed-byte data from a part of print data information by a one-way function. In the multifunctional copying machine provided with the printer or printer function of Claim 7,
A printer or a multi-function copying apparatus having a printer function, characterized by comprising a comparison means for comparing data between a hash value input from the IC card or the removable medium and an internally generated hash value. In the multifunctional copying machine provided with the printer or printer function of Claim 10,
The print data information transferred from the user information processing apparatus is stored in a data storage unit. When the data comparison results are the same, a print process is performed. After the print process is completed, the print data information of the data storage unit is stored. A multi-function copying apparatus having a printer or printer function characterized by erasing.   A security printing system comprising the printer according to claim 11 or a multi-function copying apparatus having a printer function, an IC card according to claim 8, and an information processing apparatus according to claim 9. A user information processing apparatus and a printer or a multi-function copying apparatus having a printer function are connected via a network, and print data information is transferred from the user information processing apparatus to the printer or the multi-function copying apparatus, and the print data information A function of acquiring a part of the print data information from the user information processing apparatus and generating constant byte length data from the part of the print data information by a one-way function. With removable media,
A multi-function copying apparatus having a printer or printer function according to claim 11;
In the security printing system comprised by the information processing apparatus of Claim 9,
The security printing system, wherein the removable medium is a USB memory, a compact flash (registered trademark) card or an SD card. In the multifunctional copying machine provided with the printer or printer function of Claim 7,
Any one of MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512 is used as the one-way function. A printer or a multi-function copying apparatus having a printer function. The IC card according to claim 8, wherein
Any one of MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512 is used as the one-way function. The information processing apparatus according to claim 9.
Any one of MD2, MD4, MD5, SHA-1, SHA-256, SHA-384, and SHA-512 is used as the one-way function. A security printing system using the printer according to claim 7 or a multi-function copying apparatus having a printer function, the IC card according to claim 8, or the information processing apparatus according to claim 9.
The security printing system, wherein the print data information used for generating the hash value includes at least print data information generation time information in the user information processing apparatus. In the multifunctional copying machine provided with the printer of Claim 7 or 10 or 11, or a printer function,
A printer or printer function characterized in that when the print data information transferred from the user information processing apparatus is not subjected to print processing within a predetermined time, the print data information of the data storage means is automatically deleted. Multifunctional copying machine.   19. A security printing characterized in that a notice on the screen of the user information processing apparatus is automatically displayed that the print data information of the data storage means in the printer or multi-function copying apparatus having a printer function according to claim 18 is automatically deleted. system.

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