JP2007060046A - Facsimile device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facsimile device in which the leakage of image data can be prevented exactly. <P>SOLUTION: The facsimile device comprises a section 110 for receiving the designation of the encrypted transmission or normal transmission of transmission object image data, an encryption processing section 112, a section 114 for storing the image data before transmission, and a write control section 116 for storing the image data as they are in the data storage section 114 when the transmission designation receiving section 110 has received the designation of normal transmission, but encrypting the image data at the encryption processing section 112 when the transmission designation receiving section 110 received the designation of encrypted transmission and storing the image data in an encrypted state in the data storage section 114. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a facsimile apparatus capable of encrypting and transmitting image data.

  In recent years, facsimile apparatuses that transmit image data after encryption are known. In this type of facsimile apparatus, generally, image data read by an image reading unit or the like is stored in a storage unit, and the image data is encrypted at the time of transmission.

In addition, as a facsimile apparatus with improved confidentiality, a wireless terminal apparatus is installed outside the facsimile apparatus and encrypted image data is stored in the wireless terminal apparatus (for example, Patent Document 1). reference). In this facsimile apparatus, when the transmission time comes, the encrypted image data is received from the wireless terminal device, decrypted, and then transmitted to a predetermined transmission destination.
JP 2005-12440 A

However, since the facsimile apparatus described in Patent Document 1 receives the encrypted data from the wireless terminal apparatus and performs the decryption process in the own apparatus, it holds the decrypted image data in the own apparatus. Become. That is, there is a problem that unencrypted image data is held in the apparatus, and the image data may be leaked due to unauthorized access by a third party or the like.
In addition, since it is necessary to separately provide a wireless terminal device and to transmit and receive image data to and from the wireless terminal device, there is a problem that the system becomes large and manufacturing cost and installation space increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a facsimile apparatus capable of accurately preventing leakage of image data.

According to the present invention that solves the above-described problem, for image data to be transmitted, a transmission instruction reception unit that receives designation of encrypted transmission or normal transmission, an encryption processing unit that performs encryption processing, and the image before transmission When the data storage unit for storing data and the transmission instruction reception unit receive the designation of normal transmission, the image data is stored in the data storage unit without being encrypted, and the transmission instruction reception unit performs encrypted transmission. A writing control unit that encrypts the image data in the encryption processing unit and stores the image data in an encrypted state in the data storage unit when the designation is accepted Is provided.
Note that “encrypted transmission” here means transmission in an encrypted state at the time of transmission, and “normal transmission” here means an item that does not need to be transmitted in an encrypted state at the time of transmission. Say.

According to the present invention, when the transmission instruction receiving unit receives the designation of encrypted transmission, the image data is encrypted by the writing control unit, and the image data is stored in the data storage unit in an encrypted state. Then, the encrypted image data is transmitted to a predetermined transmission destination at a predetermined timing. As a result, the image data designated for encrypted transmission is held in an encrypted state in the data storage unit. Note that the data storage unit here refers to a unit that holds image data for a certain period until transmission, and does not include, for example, a unit used for temporary storage such as a reading memory.
Therefore, there is no non-encrypted image data in the data storage unit between the time the image data is received and the time it is transmitted, and a third party or the like illegally obtains the unencrypted image data. It is not possible.
When the transmission instruction accepting unit accepts the designation of normal transmission, the image data is stored in the data storage unit without being encrypted by the writing control unit.

  The facsimile apparatus may include a reservation transmission unit that transmits the image data stored in the data storage unit at a set time.

  According to this configuration, the image data is held in the data storage unit in an encrypted state until the image data is transmitted by the reservation transmission unit. Thereby, even if image data is stored in the data storage unit for a relatively long time during transmission reservation, a third party or the like cannot illegally acquire image data that is not encrypted, It is effective for maintaining confidentiality of image data.

  In the facsimile apparatus, an output instruction receiving unit that receives an output instruction for the image data stored in the data storage unit, an output unit that outputs the image data for which the output instruction receiving unit has received an output instruction, and the output If the image data for which the instruction receiving unit has received the output instruction is in an encrypted state, the authentication unit that receives authentication information for decryption and performs authentication, and the image data in the encrypted state A decoding processing unit that performs the decoding processing of the image data, and the output unit, when authenticated by the authentication unit, decodes the image data that has received the output instruction by the decoding processing unit, The converted image data can be output.

  According to this configuration, when the output instruction is received by the output instruction receiving unit, the image data for which the output instruction has been received is output, so that the user of the apparatus checks the image data during transmission reservation, standby for transmission, etc. be able to. Here, when the image data stored in the data storage unit is in an encrypted state, the image data is not decrypted unless authentication is input and authentication is performed. Therefore, the confidentiality of the image data can be ensured.

  The facsimile apparatus may include a deletion unit that deletes the image data from the data storage unit when the image data stored in the data storage unit is transmitted to the outside.

  According to this configuration, since the image data in the data storage unit is erased after transmission, no information regarding the image data remains in the data storage unit, and the confidentiality is further improved.

  The facsimile apparatus includes a temporary storage unit that temporarily stores the image data, and the writing control unit is configured to process the image data when the transmission instruction receiving unit receives designation of encrypted transmission, The image data in an unencrypted state can be expanded in the temporary storage unit, and the image data can be stored in the data storage unit in an encrypted state.

  According to this configuration, when processing image data such as encryption processing, a work area for handling unencrypted image data is required. However, unencrypted image data is temporarily stored. Since the processing operation is performed by developing the data in the storage unit, there is no unencrypted image data in the data storage unit.

  In the facsimile apparatus, the writing control unit creates a management table related to attribute information of the image data in an unencrypted state when the transmission instruction receiving unit receives designation of encrypted transmission. It can be set as the structure memorize | stored in a memory | storage part.

  According to this configuration, since the attribute information about the image data is recorded in the management table when the image data is encrypted and stored in the data storage unit, the process such as decryption of the encrypted image data is performed. Can be performed based on the attribute information of the original image data that has not been encrypted with reference to the management table, and the processing efficiency of the image data is dramatically improved.

  The facsimile apparatus includes an encoding processing unit that encodes image data received from outside the apparatus by the transmission instruction receiving unit, and the writing control unit is configured to specify the encrypted transmission by the transmission instruction receiving unit. When accepted, the image data is encoded by the encoding processing unit, the encoded image data is encrypted by the encryption processing unit, and the image data is encoded and encrypted It can be set as the structure memorize | stored in the said data storage part.

  According to this configuration, in the case of encrypted transmission, the image data is once encoded and then encrypted and stored in the data storage unit. In the case of normal transmission, the image data is stored in the data storage unit without being encrypted in an encoded state.

  In the facsimile apparatus, a conversion processing unit that converts the image data encoded by the encoding processing unit into a predetermined transmission format, and a decoding processing unit that performs a decoding process of the image data in an encrypted state. And the writing control unit stores the image data in the encoded and encrypted state in the data storage unit when the transmission instruction receiving unit receives the designation of encrypted transmission, The image data is read from the data storage unit and expanded into the temporary storage unit while being decrypted by the decryption processing unit, the image data is converted by the conversion processing unit, and the converted image data is converted to the encryption The encryption processing unit can encrypt the data and store the data in the data storage unit.

  According to this configuration, in the case of encrypted transmission, the image data that has been encoded and encrypted and stored in the data storage unit is decrypted and expanded in the temporary storage unit in an unencrypted state. As a result, the image data can be converted by the conversion processing unit. Then, the image data is converted by the conversion processing unit using the temporary storage unit as a work area, and the converted image data is encrypted again by the encryption processing unit and stored in the data storage unit. As a result, the image data converted into the predetermined transmission format and encrypted can be held in the data storage unit without the presence of unencrypted image data in the data storage unit.

  As described above, according to the present invention, image data for which encrypted transmission is designated is always stored in an encrypted state in the storage unit. Can be prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

FIG. 1 is a functional block diagram of a facsimile apparatus showing an embodiment of the present invention.
As shown in FIG. 1, a facsimile apparatus 100 includes a reading unit 102 that reads an image of a document and generates image data, a printing unit 104 that prints an image based on the image data, and a personal computer through a network such as a LAN or the Internet. And a communication unit 106 that communicates with an external terminal such as a computer or another facsimile machine. The facsimile machine 100 is called a “network facsimile machine” because it performs facsimile communication with other facsimile machines via a network.

  The facsimile apparatus 100 also includes a temporary storage unit 108 that temporarily stores data and the like during processing of data and the like, and a transmission instruction reception unit 110 that receives designation of encrypted transmission or normal transmission for image data to be transmitted. An encoding processing unit 140 that performs encoding processing of image data received from the outside of the apparatus by the transmission instruction receiving unit 110, and converts the image data encoded by the encoding processing unit 140 into a predetermined transmission format. Conversion processing unit 142, encryption processing unit 112 that performs encryption processing, decryption processing unit 130 that performs decryption processing of image data in an encrypted state, and data storage unit that stores image data before transmission 114 and a writing control unit 116 that controls writing of the image data received by the transmission instruction receiving unit 110 to the data storage unit 114.

  The temporary storage unit 108 includes a volatile memory such as SDRAM or DRAM, and is used when the reading unit 102 generates image data. Specifically, the reading unit 102 accumulates the read image data in the temporary storage unit 108 and encodes the data in the area of the temporary storage unit 108.

  The transmission instruction reception unit 110 receives designation of encrypted transmission and normal transmission by an operation input from the input unit 118 such as an operation button, a switch, a lever, a keyboard, or a touch panel. In addition, the transmission instruction receiving unit 110 acquires image data to be transmitted from the reading unit 102.

  The encoding processing unit 140 is, for example, a codec, and encodes image data read by the reading unit 102 into facsimile-type compressed image data. In the present embodiment, the reading unit 102 is a scanner, and the encoding processing unit 140 encodes image data read by the scanner for each page. The conversion processing unit 142 performs conversion of the encoded image data into the TIFF format and conversion into the MIME format.

  The encryption processing unit 112 encrypts image data and the like based on the encryption key stored in the key storage unit 120. Further, the decryption processing unit 130 decrypts image data and the like based on the encryption key. When performing e-mail communication, the encryption processing unit 112 encrypts the entire header, body, and attached file constituting the e-mail. In the present embodiment, as an encryption method, S / MIME is used for electronic mail, and PGP method is used for other than electronic mail. The encryption may be MOSS or PEM, and is not limited to a predetermined method. The key storage unit 120 stores information about the common key and information about the public key. The encryption processing unit 112 performs data encryption processing using a common key and data encryption processing using a public key.

  Here, the common key is an encryption key shared by encryption and decryption. That is, data encrypted with a predetermined common key is decrypted using the same common key. In the present embodiment, the same common key is used on the facsimile machine 100 side and the transmission destination side. As a result, data can be encrypted and decrypted on both the facsimile apparatus 100 side and the transmission destination side.

  The public key is an encryption key that has a secret key to be paired. That is, data encrypted with one of the public key and the private key cannot be decrypted without using the other. In this embodiment, the public key corresponding to the transmission destination is stored in the key storage unit 120, and the above-mentioned common key is encrypted at the time of transmission.

  The data storage unit 114 is a non-volatile memory and stores image data such as a transmission reservation and a transmission standby. Specifically, the data storage unit 114 is a hard disk. In the case of encrypted transmission, encrypted image data is stored, and in the case of normal transmission, unencrypted image data is stored.

  The writing control unit 116 stores the image data in the data storage unit 114 without encryption when the transmission instruction receiving unit 110 receives designation of normal transmission. Further, when the transmission instruction receiving unit 110 receives the designation of encrypted transmission, the writing control unit 116 creates a management table related to attribute information of image data in an unencrypted state and stores it in the data storage unit 114. At the same time, the image data is encrypted by the encryption processing unit 112, and the image data is stored in the data storage unit 114 in an encrypted state. When the transmission instruction receiving unit 110 receives the designation of encrypted transmission, the writing control unit 116 expands the unencrypted image data in the temporary storage unit 108 when processing the image data, and the data storage unit In 114, the image data is stored in an encrypted state. Here, a common key is used for encryption of image data.

  Specifically, the writing control unit 116 causes the encoding processing unit 140 to encode the image data when the transmission instruction receiving unit 110 receives the designation of normal transmission, and the encoded image data to the encryption processing unit. The data is encrypted at 112 and stored in the data storage unit 114. Thereafter, the image data is read out from the data storage unit 114, decoded by the decoding processing unit 130, expanded in the temporary storage unit 108, converted by the conversion processing unit 142, and converted image data. Is encrypted by the encryption processing unit 112 and stored in the data storage unit 114.

  Further, the facsimile apparatus 100 includes an output instruction receiving unit 122 that receives an output instruction for image data stored in the data storage unit 114, an output unit 124 that outputs image data for which the output instruction receiving unit 122 has received an output instruction, Have The output instruction receiving unit 122 receives an output instruction by an operation input from the input unit 118 such as an operation key. The output unit 124 outputs the image data to the printing unit 104 or the display unit 126. Here, the display unit 126 is made of, for example, liquid crystal, and displays the operation state of the apparatus, image data, and the like.

  In addition, the facsimile apparatus 100 includes an authentication unit 128 that receives authentication information for decryption and performs authentication when the image data for which the output instruction reception unit 122 has received the output instruction is in an encrypted state. ing. The authentication information may be a password set according to the user or the transmission destination, or may be biometric information such as a fingerprint.

  Then, when the authentication unit 128 authenticates, the output unit 124 decodes the image data for which the output instruction has been received by the decoding processing unit 130, and outputs the decoded image data.

  Furthermore, the facsimile machine 100 includes a reservation transmission unit 132 that transmits the image data stored in the data storage unit 114 at a set time. The reservation transmission unit 132 has a function of transmitting image data at a time designated by an operation input from the input unit 118, and after transmission of other data when receiving transmission of image data during transmission of other data. A function of automatically transmitting image data. In addition, the facsimile machine 100 includes an erasing unit 134 that erases image data from the data storage unit 114 when image data stored in the data storage unit 114 is transmitted.

  Each component of the facsimile machine 100 includes a built-in CPU, a memory, a program that realizes each component, a storage unit that stores the program, and an arbitrary combination of hardware and software, mainly an interface for network connection. Realized. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus. FIG. 1 shows functional unit blocks instead of hardware units.

The operation of the facsimile apparatus 100 configured as described above will be described with reference to the flowchart shown in FIG. This flowchart shows the flow of transmission processing for one piece of image data.
As shown in FIG. 2, when the transmission instruction receiving unit 110 receives an image data transmission instruction (step S10), it is determined whether or not a data transmission destination is input (step S20). When the transmission destination is not input, the process proceeds to step S20 and waits for input of the transmission destination.

  If it is determined in step S20 that the transmission destination has been input, the transmission instruction reception unit 110 determines whether or not designation of encrypted transmission has been received (step S30). At this time, if it is determined that the designation of encrypted transmission has been received, the image processing unit 112 encrypts the image data (step S40). This encryption is promptly performed when the reading unit 102 receives image data. The image data encrypted in step S40 is stored in the data storage unit 114 (step S50). If it is determined in step S30 that the designation of encrypted transmission has not been accepted, that is, the designation of normal transmission has been accepted, the process proceeds to step S50, and the image data is stored in the data storage unit 114 in an unencrypted state. Accumulated.

  Here, document reading processing, encryption processing, transmission conversion processing, and the like related to steps S40 and S50 will be described in detail. As described above, the image read by the reading unit 102 is accumulated in the temporary storage unit 108, and encoding by the encoding processing unit 140 is performed page by page. When this encoding is completed, attribute data such as the amount of encoded data, the encoding method, the resolution, and the number of lines are stored in the data storage unit 114 as a management table. Then, the encoded image data is read from the temporary storage unit 108, encrypted by the PGP method, the image data is stored in the data storage unit 114, and this operation is repeated until all the transmission originals are read. As described above, in the case of encrypted transmission, the image data is once encoded and then encrypted and stored in the data storage unit 114.

  In the present embodiment, the image data stored in the data storage unit 114 is converted into TIFF format and MIME format as the conversion processing for transmission of the image data. Here, when image data is transmitted and received between the temporary storage unit 108 and the data storage unit 114, the image data in an unencrypted state is processed by performing decryption and encryption processing of the image data. It does not exist in the storage unit 114.

  Specifically, first, based on the attribute data of each page of the management table stored in the data storage unit 114, a TIFF format header or the like is generated in the area of the temporary storage unit 108 and stored in the data storage unit 114. The stored encrypted data is decrypted while being read out and combined with a header or the like in the temporary storage unit 108 area. As described above, in the case of encrypted transmission, the image data that has been encoded and encrypted and stored in the data storage unit 114 is expanded into the temporary storage unit 108 without being decrypted. As a result, the image data can be converted by the conversion processing unit 142. Then, a TIFF file is generated in the temporary storage unit 108, and the file is encrypted and stored in the data storage unit 114. Further, the data amount of the TIFF format file is written in the management table, and the conversion process to the TIFF format ends.

  When the conversion to the TIFF format is completed, a MIME format header or the like is subsequently generated in the area of the temporary storage unit 108 based on the attribute data of the management table stored in the data storage unit 114, and the data storage unit The encrypted data in the TIFF format stored in 114 is decrypted while being read out, and is combined with a header or the like in the area of the temporary storage unit 108. Then, a MIME format file is generated in the temporary storage unit 108, and the file is encrypted and stored in the data storage unit 114. As a result, the image data is encrypted and stored in a format that can be transmitted by e-mail.

  In this way, the image data is converted by the conversion processing unit 142 using the temporary storage unit 108 as a work area, and the converted image data is encrypted again by the encryption processing unit 112 and stored in the data storage unit 114. As a result, the image data converted into the predetermined transmission format and encrypted can be held in the data storage unit 114 without causing the data storage unit 114 to have unencrypted image data. In normal transmission not via step S40, processing similar to the above is performed except for decryption and encryption processing.

  After step S50, the output instruction receiving unit 122 determines whether an output instruction has been received for the image data stored in the data storage unit 114 (step S60). If it is determined in step S60 that an output instruction has been received, it is then determined whether or not the image data for which the output instruction has been received is encrypted (step S70). If it is determined in step S70 that the image data is encrypted, the display unit 126 displays that the authentication information can be input, shifts to the authentication information input mode, and accepts the input of authentication information ( Step S80). Next, it is determined whether or not the input authentication information is authentic (step S90). If it is determined that the authentication information is authentic, the image data is decoded (step S100), and then the image data is output (step S110). ). If it is determined that the authentication information input in step S90 is not authentic, the process proceeds to step S60 to determine again whether an output instruction has been accepted. If it is determined in step S70 that the image received the output instruction is not encrypted, the process proceeds to step S110 to output image data.

  When it is determined in step S60 that an output instruction has not been received, or after image data is output in step S110, it is determined whether or not a transmission start condition is satisfied (step S120), and the transmission start condition is satisfied. Is determined, the image data stored in the data storage unit 114 is transmitted to the outside (step S130). As described above, this transmission start condition is that when the transmission time is specified, it is one of the conditions that the time is reached, and when waiting for transmission processing of other data, transmission of other data is performed. One of the conditions is that the processing is completed. At the time of transmission to the outside, a common key for decrypting image data is encrypted with a public key set according to the transmission destination. When it is determined in step S120 that the transmission start condition is not satisfied, the process proceeds to step S60 and enters a transmission standby state.

  After transmitting the image data in step S130, it is determined whether or not a transmission error has occurred (step S140). If it is determined in step S140 that a transmission error has occurred, the process proceeds to step S30 to repeat a series of transmission processes. If it is determined in step S140 that no transmission error has occurred, the image data stored in the data storage unit 114 is deleted (step S150).

  As described above, according to the facsimile apparatus 100 of the present embodiment, when the designation of the transmission instruction receiving unit 110 encrypted transmission is received, the image data is encrypted by the writing control unit 116, and the image data is encrypted. The state is stored in the data storage unit 114. Then, when the transmission start time comes, the encrypted image data is transmitted to the input transmission destination. As a result, the image data designated for encrypted transmission is always held in an encrypted state in the data storage unit 114. When the transmission instruction accepting unit 110 accepts the designation of normal transmission, the image data is directly stored in the data storage unit 114 by the writing control unit 116.

In addition, when processing image data such as encryption processing, a work area for handling unencrypted image data is required. Therefore, unencrypted image data is stored in the temporary storage unit 108. Since the processing operation is performed by expanding, there is no unencrypted image data in the data storage unit 114.
Therefore, the image data that is not encrypted does not exist in the data storage unit 114 that is a volatile memory between the time when the image data is received and the time when the image data is transmitted. Data cannot be obtained illegally. Thereby, the leakage of the image data is prevented accurately.

  Further, according to the facsimile apparatus 100 of the present embodiment, when image data is encrypted and stored in the data storage unit 114, the attribute information related to the image data is recorded in the management table, and thus encrypted. When performing processing such as decryption of image data, processing can be performed based on the attribute information of the original image data that has not been encrypted with reference to the management table, and the processing efficiency of the image data has been dramatically increased. improves.

  Further, the image data is held in the data storage unit 114 in an encrypted state until the image data is transmitted by the reservation transmission unit 132. As a result, even if image data is stored in the data storage unit 114 for a relatively long period of time during transmission reservation, a third party or the like cannot illegally obtain unencrypted image data. It is effective for maintaining confidentiality of image data.

  Further, when the output instruction is received by the output instruction receiving unit 122, the image data for which the output instruction has been received is output, so that the user of the apparatus can check the image data during transmission reservation, waiting for transmission, and the like. . Here, when the image data stored in the data storage unit 114 is in an encrypted state, the image data is not decrypted unless authentication is input and authentication is performed. Therefore, the confidentiality of the image data can be ensured.

  In the above embodiment, the facsimile apparatus 100 is exemplified as one that performs facsimile communication via a network. However, it is needless to say that the facsimile apparatus 100 may perform facsimile communication via a public communication network.

  In the above-described embodiment, the reading unit 102 is a scanner and reads a document image to be transmitted. However, for example, a personal computer external to the apparatus connected via a network can be connected via the communication unit 106. The image data to be transmitted may be received. In this case, when the encrypted transmission is received in an already encrypted state, the image data may be stored in the data storage unit 114 as it is, or if it is received in an unencrypted state, the image data is temporarily stored. The data may be encrypted in the storage unit 108 and stored in the data storage unit 114.

  In the embodiment, the image data is encrypted using the common key. However, the image data may be encrypted using the transmission destination public key. Image data encrypted using the transmission destination public key cannot be decrypted unless there is a corresponding private key. In order to provide the facsimile apparatus 100 with a function of decrypting image data in this manner, for example, in addition to what is encrypted using the public key of the transmission destination, the image data is encrypted using the public key of the facsimile apparatus 100. The converted data may be stored in the data storage unit 114. As a result, the image data can be decrypted using the secret key of the facsimile apparatus 100.

  In the above-described embodiment, the data storage unit 114 is a hard disk. However, other non-volatile memories such as a compact flash (registered trademark) and an SD card may be used. Furthermore, the data storage unit 114 may be a volatile memory such as a backed up DRAM or the like, and it is needless to say that other specific detailed structures can be appropriately changed.

1 is a functional block diagram of a facsimile apparatus showing an embodiment of the present invention. 3 is a flowchart showing the operation of the facsimile apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Facsimile apparatus 102 Reading part 104 Printing part 106 Communication part 108 Temporary storage part 110 Transmission instruction | indication reception part 112 Encryption processing part 114 Data storage part 116 Write control part 118 Input part 120 Key storage part 122 Output instruction | indication reception part 124 Output part 126 Display Unit 128 Authentication Unit 130 Decoding Processing Unit 132 Reservation Transmission Unit 134 Erasing Unit 140 Encoding Processing Unit 142 Conversion Processing Unit

Claims (8)

A transmission instruction accepting unit that accepts designation of encrypted transmission or normal transmission for image data to be transmitted;
An encryption processing unit for performing encryption processing;
A data storage unit for storing the image data before transmission;
When the transmission instruction accepting unit accepts designation of normal transmission, the image data is stored in the data storage unit without encryption, and when the transmission instruction accepting unit accepts designation of encrypted transmission, the image And a writing control unit that encrypts data in the encryption processing unit and stores the image data in an encrypted state in the data storage unit.   The facsimile apparatus according to claim 1, further comprising a reservation transmission unit that transmits the image data stored in the data storage unit at a set time. An output instruction receiving unit that receives an output instruction of the image data stored in the data storage unit;
An output unit that outputs the image data for which the output instruction receiving unit has received the output instruction;
An authentication unit for receiving and authenticating an input of authentication information for performing decryption when the image data for which the output instruction receiving unit has received the output instruction is in an encrypted state;
A decryption processing unit that performs decryption processing of the image data in an encrypted state,
The output unit according to claim 1 or 2, wherein when the authentication unit authenticates, the output unit receives the output instruction, decodes the image data by the decoding processing unit, and outputs the decoded image data. The described facsimile machine.   The facsimile according to any one of claims 1 to 3, further comprising an erasing unit that erases the image data from the data storage unit when the image data stored in the data storage unit is transmitted to the outside. apparatus. A temporary storage unit for temporarily storing the image data;
When the transmission instruction accepting unit accepts designation of encrypted transmission, the writing control unit expands the image data in an unencrypted state in the temporary storage unit when processing the image data, The facsimile apparatus according to any one of claims 1 to 4, wherein the image data is stored in an encrypted state in a data storage unit.   The write control unit creates a management table related to attribute information of the image data in an unencrypted state and stores the management table in the data storage unit when the transmission instruction reception unit receives designation of encrypted transmission The facsimile apparatus according to claim 5. An encoding processing unit that encodes image data received from outside the apparatus by the transmission instruction receiving unit;
When the transmission instruction accepting unit accepts the designation of encrypted transmission, the writing control unit causes the encoding processing unit to encode the image data, and the encoded image data is subjected to the encryption processing. The facsimile apparatus according to claim 5 or 6, wherein the image data is encrypted and stored in the data storage unit in an encoded and encrypted state. A conversion processing unit that converts the image data encoded by the encoding processing unit into a predetermined transmission format;
A decryption processing unit that performs decryption processing of the image data in an encrypted state,
When the transmission instruction accepting unit accepts the designation of encrypted transmission, the write control unit stores the image data in the encoded and encrypted state in the data storage unit, and then from the data storage unit The image data is read out and expanded in the temporary storage unit while being decrypted by the decryption processing unit, the image data is converted by the conversion processing unit, and the converted image data is transferred to the encryption processing unit. 8. The facsimile apparatus according to claim 7, wherein the facsimile apparatus is encrypted and stored in the data storage unit.

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