JPH03232380A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To enable communication with both of a facsimile equipment equipment with a cipher processing function and a facsimile equipment without the cipher processing function by connecting a cipher processing means while controlling a switch means when the communication is started, separating the cipher processing means when a control signal from a called party equipment can not be recognized, and holding the state afterwards. CONSTITUTION:Both transmission and reception sides are set so as to output the signal of a switch circuit 16-a to a ciphering device 17-a and to output a signal from the ciphering device 17-a to a modulation circuit 5 by a switch circuit 16-b in the initial state. Then, a switch circuity 16-c is set to output the signal from a demodulation circuit 8 to a decoder 17-b and a switch circuit 16-d is set to output the signal from the decoder 17-b to a received data control circuit 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile device capable of encrypting facsimile communication information.

[Prior Art] Conventional facsimile communication is carried out using a transmission control procedure in accordance with CCITT Recommendation T.30, and its greatest feature is that it can communicate with an unspecified number of other facsimile devices via the public telephone network. .

However, for some specific users, such as those working in the government and banks, due to the nature of their work, it is necessary to keep the contents of their communications confidential even in facsimile communications. For these users, in order to keep the contents of the communication confidential, there is a method of connecting an encryption device to the facsimile machine to prevent connections with unintended faxes due to incorrect dialing, or eavesdropping, and encrypting the facsimile communication before sending it. has traditionally been practiced.

This conventional facsimile machine capable of encrypted communication is
This will be explained below with reference to the figures.

In the following explanation, the facsimile machine having the configuration shown in FIG.
An example of transmitting image information to another facsimile device 60 via the public telephone line 50 and the transmission path 52 will be described.

Conventional facsimile machines of this type encrypt all communication information before transmitting it. Therefore, an encrypted control signal sent from another facsimile device 60, which is a facsimile device on the receiving side, via the transmission path 52, the public telephone line network 50, and the transmission path 51 at a transmission speed of, for example, 300 bps. is sent from the NCU 6 to the demodulation circuit 8. After being demodulated by the demodulation circuit 8, the data is input to the decoder 17-b, where the encrypted data is returned to the original data and sent to the reception data control circuit 9. Reception data control circuit 9
After being deframed, the signal is analyzed by the control signal analysis section 10. A flow control unit 1 controls the entire facsimile machine according to a control procedure built in the ROM 12.
Sent to 1.

The flow control unit 11 causes the control signal generation unit 2 to generate a corresponding control signal to be transmitted to the receiving side according to the control signal analyzed by the control signal analysis unit 10. The generated control signal is sent to the transmission data control circuit 4 via the switching circuit 3 and subjected to framing processing. Thereafter, the data is sent to the encoder 17-a, where a predetermined encryption process is performed. This encrypted information is modulated by the modulation circuit S and then transmitted to another facsimile device 60 on the receiving side via the NCU 6.

When the pre-procedure processing performed before transmitting the image signal is executed in this way, the image signal read by the reading section 1 (or the image signal stored in advance in the RAM 13) is transferred to the switching circuit 3. Following the same route as the control signal described above, the encoder 17-a encrypts it and sends it to the other facsimile machine 60.

On the receiving side of this image signal, the received image signal is sent from the NCU 6 to the demodulation circuit 8, demodulated by the demodulation circuit 8, and then sent to the decoder 17.
-b returns the encrypted data to the original data and sends it to the reception data control circuit 9. Thereafter, the received image signal is sent to the recording section 15, where it is printed out on recording paper or the like.

Conventionally, all communication data is encrypted as described above, and facsimile communication is performed using only the encrypted data.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, since the encryption device for ensuring communication secrecy is fixedly connected, there are the following drawbacks.

(1) When a call is established between a facsimile machine to which an encryption device is not connected, even if one sends or receives a call, the other party will not be able to recognize the content of the communication at all, and the communication will be interrupted. This will not work properly and will end with an error. However, even in such a case, the operator did not know why the process ended in error.

(2) To communicate with a facsimile machine to which no encryption device is connected, search for another facsimile device to which no encryption device is connected, or open the lid of the facsimile device, etc. This required extensive operations, such as removing the encryption device cable and connecting a bypass cable instead.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and includes the following configuration as one means for solving the above-mentioned problems.

That is, a cryptographic processing means that encrypts transmitted data and decrypts the encrypted data is connected to the cryptographic processing means to encrypt/decrypt the transmitted and received data, or the cryptographic processing means is separated and the transmitted data is and a switch means for switching whether or not to send and receive the data without encrypting it.

Further, the control means is provided for controlling the switch means to connect the cryptographic processing means at the start of communication, for disconnecting the cryptographic processing means by the switch means when the control signal from the partner device cannot be recognized, and for maintaining this state thereafter.

Furthermore, a prohibition means is provided for prohibiting the control means from disconnecting the cryptographic processing means of the switch means when performing a transmission operation.

[Operation] With the above configuration, it is possible to communicate with either a facsimile machine equipped with a cryptographic processing function or a facsimile machine without a cryptographic processing function without physically removing the cryptographic processing means.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Description of facsimile device (FIG. 1)> FIG. 1 is a block diagram of a facsimile device in this embodiment. In this figure, the same components as in FIG. 5 are given the same numbers.

In the figure, 1 is a reading unit that reads image data, converts it into a corresponding electrical signal, and outputs it; 2 is a control signal generator that generates various communication control signals for controlling facsimile communication;
3 is a switching circuit that is controlled by the flow control unit 11 and selects either the image signal read by the reading unit 1 or the control signal generated by the control signal generation unit 2 and outputs it to the transmission data control circuit 4. , 4 is a transmission data control circuit that converts the output signal of the switching circuit 3 into a transmission data format defined by a known facsimile communication standard, and 5 is a transmission data control circuit that modulates the binary transmission data and outputs it to the switch circuit 16-a. modulation circuit, 6
is the NCU (Network Co.
8 is a demodulation circuit that demodulates a modulated signal sent from, for example, the other party's device (another facsimile device 60, etc.) via a line network 50 and a transmission path 51; a received data control circuit that converts the received data into a processing format for its own device; 10;
11 is a control signal analysis unit that extracts and analyzes a communication control signal from the output signal of the received data control circuit 9, and 11 controls the entire facsimile apparatus including transmission control procedure control, which will be described later, according to control procedures stored in the ROM 12. 12 is a ROM that stores the processing procedures of the flow control unit 11, 13 is a RAM used as a work area when the flow control unit 11 executes processing, and 14 is a RAM used by the operator to store various information on the facsimile machine. 15 is a recording unit that records received image data or image data read by the reading unit 1; 16-a=d is a flow control unit 1;
a switch circuit that switches the signal route by controlling 1;
17-a is an encoder that performs predetermined encryption processing on transmission data and encrypts it; 17-b is a decoder that returns encrypted received data to the original data before being encrypted. be.

Further, 50 is a public telephone network that accommodates connection lines for an unspecified number of facsimile machines, etc., 51 is a two-wire transmission line that is accommodated in the line network 50, and 60 is a network that is connected to the line network 50, etc. This is a facsimile machine.

In this embodiment, the operation mode of the device can be freely set by inputting instructions from the operation unit 14.

For example, when performing facsimile communication with the other party, there is a mode in which the transmitted and received data is always encrypted at first, and if pre-procedure signals etc. cannot be received normally, normal facsimile communication is performed without encryption, or the other party's device If the controller does not have an encryption function and the pre-procedure signal etc. cannot be received normally, the operator's instructions can be sought and a mode etc. for determining subsequent control can be selected.

<Explanation of operation (Figures 2 to 4)> The transmission and reception operations in this embodiment with the above configuration are as follows.
This will be explained below with reference to FIGS. 2 to 4. In FIGS. 2 to 4, the calling station is shown on the left, and the called station is shown on the right.

First, with reference to FIG. 2, communication control when both the sending facsimile machine and the receiving facsimile machine are equipped with an encryption processing function will be explained. Note that FIG. 2 shows communication control when the device of this embodiment is the calling side and transmits an image signal.

In this embodiment, the flow control unit 11 controls the switch circuit 16-b so that the output of the switch circuit 16-a is connected to the encoder 17-a in the initial state of both the transmitting and receiving sides.
is set to output the signal from the encoder 17-a to the modulation circuit 5, the switch circuit 6-c outputs the signal from the demodulation circuit 8 to the decoder 17-b, and the switch circuit 16-d is set to output the signal from the demodulation circuit 8 to the decoder 17-b. The signal from the receiver 17-b is set to be output to the received data control circuit 9.

First, a known calling process is performed, for example, the apparatus of this embodiment calls another facsimile apparatus 60, the other facsimile apparatus 60 responds, and a communication path is established between the apparatuses. When a communication path is established between the devices, the other facsimile device 60 first transmits a known pre-procedure signal 101 (for example, NSF, DIS, etc.) encrypted by the encoder 17-a to the calling device.

This pre-procedure signal 101 is a signal sent at a transmission rate of 300 bps to the calling side device that has the functions of the called side device. It is possible to transmit whether or not the side device has an encryption function as shown in FIG. Since the format at this time is well known, detailed explanation will be omitted.

This pre-procedure signal is sent to the demodulation circuit 8 via the NCU 6 of the calling side device, where it is demodulated and converted into a binary code, and sent to the decoder 17-b via the switch circuit 16-c. It will be done. Then, the signal is returned to the original signal before encryption and sent to the reception data control circuit 9 via the switch circuit 16-d. Here, it is deframed and sent to the control signal analysis section 10, where the control signal is analyzed and the flow control section 1
Sent to 1.

When the flow control unit 11 confirms that the called device has an encryption function based on the analysis result, it sends a procedure signal 102 (for example, NS
S, DO3, etc.) are generated by the control signal generator 2. This generated signal is sent to the transmission data control circuit 4 via the switching circuit 3, where it is framed, and then sent to the encoder 17-a via the switching circuit 16-a, where it is encrypted. . After that, it is modulated by the modulation circuit 5 and the NCU 6
, the transmission line 51, the line network 50, and the transmission line 52 to the called device.

The pre-procedure signal 102 transmits to the receiving side a signal instructing the communication mode for subsequent image signal transmission, and the like.

Subsequently, the flow control unit 1 that sent the previous procedure signal 102
1 instructs the control signal generator 2 to generate a training check signal, encrypts it with the encoder 17-a, and then applies necessary modulation in the modulation circuit 5 to generate the encrypted training check signal 103. Send to the called party (receiving party).

The training check signal 103 indicates the current communication speed,
This is to check whether the receiving side can normally receive image signals according to the communication specifications.

The other facsimile machine on the receiving side that has received this encrypted training check signal 103 returns an encrypted reception readiness confirmation signal (CFR) etc. shown in 104 to the sending side as a result of receiving the training check signal. do. On the transmitting side that has received this signal, since it has finished preparing for transmission according to the current communication specifications and is ready to send, it encrypts the read image signal etc. from the reading unit 1 as described above and sends it to the receiving side. .

At this time, the flow control unit 11 controls the switching circuit 3 so that the output to the transmission data control circuit 4 becomes the read data from the reading unit 1, and transfers the read data from the reading unit 1 to the transmission data control circuit 4, It is output as an image signal 105 to the transmission line 51 via the encoder 17-a, the modulation circuit 5, and the NCU 6.

This encrypted image signal is transferred to a line network 50, a transmission line 52
For example, it is sent to another facsimile machine 60 via the facsimile machine 60.

On the receiving side, the encrypted image signal is demodulated by the demodulation circuit 8, returned to the signal before encryption by the decoder 17-b, and sent to the recording section 15 via the received data control circuit 9.
This will result in more recorded output.

The flow control unit 11 on the sending side continues to transmit the image signal in this manner, and when the transmission of the image signal is finished, it instructs the control signal generation unit 2 to generate an end-of-procedure signal (EOP), and encrypts this signal. The encrypted procedure end signal (EOP) 106 is encrypted by the device 17-a and transmitted to the transmission path 51. The receiving side receives this procedure end signal (EOP) 106,
After being decoded by the decoder 17-b, it is analyzed by the control signal analysis section 10 on the receiving side. As a result, the receiving side flow control unit 11
This allows the transmitter to recognize that it will not send any more image signals.

Upon receiving the end-of-procedure signal (EOP) 106, the receiving device sends an encrypted image confirmation response signal (MCF) 10 to the transmitting side.
7 to notify that the procedure end signal (EOP) 106 has been received.

With the above control, communication data can be encrypted and transmitted to the other party, and the other party can also normally receive the encrypted data. This prevents secrets from being leaked to the outside.

Next, control when the calling device has the encryption function shown in FIG. 1 and the called device does not have the encryption function will be explained with reference to the flowchart in FIG. 3. .

RAM 1 is stored by the operation unit 14 of the facsimile machine
3, the device operates as a calling device, and calls the destination device. The called device does not have an encryption function, and when a communication path is established between the two devices, the called device sends an unencrypted pre-procedure signal 121 (for example, NSF).

DIS, etc.) to the calling device.In this case, the calling device also transmits the switch circuit 16-a as described above.
The states of ~16-d are encoded by the encoder 17-a and the decoder 17-b.
is set to be connected. Therefore, the called side's unencrypted pre-procedure signal is sent to the decoder 17-b.
The data is sent to , and a predetermined decoding process is performed there. At this time, as a result of decoding the unencrypted signal, the decoded signal becomes a random signal,
The received data control circuit 9 cannot perform deframing. As a result, the control signal analysis section 10 cannot analyze a significant signal, and the flow control section 11 cannot cause the control signal generation section 2 to generate a transmission side control signal.

Even in this case, the flow control unit 11 controls the demodulation circuit 8
If the other party is receiving a carrier signal from the other party, it can be recognized that the other party is a facsimile machine.Therefore, even if the called party is a facsimile machine, it may not receive a significant signal within a predetermined time. When the signal is not received, the switch circuits 16-a to 16-d are controlled and the encoder 17-a is activated.
and decoder 17-b. From then on, this state is maintained and the mode is set in which no encryption processing is performed.

On the other hand, since the called device cannot receive the unencrypted response control signal 122 from the calling party within the predetermined time (122), it again controls the unencrypted pre-procedure control signal in the same way as in 121. A signal 123 is sent to the calling device.

At this time, the calling side device has an encryptor 17-a and a decryptor 17-a.
-b is disconnected, the unencrypted pre-reception procedure control signal 123 is input to the reception data control circuit 9 via the NCU 6, demodulation circuit 8, switch circuit 16-C, and switch circuit 16-d. be done. Then, it is deframed here and sent to the control signal analysis section 10. Then, it becomes possible to analyze the pre-reception procedure control signal, and the flow control unit 1
1 can continue communication.

The subsequent steps 124 to 129 are steps for transmitting steps 102 to 107 shown in FIG. 2 described above without being encrypted, and are the same as for normal 63 facsimile.

Furthermore, communication control in the case where the facsimile device of this embodiment having an encryption processing function is the called device and the facsimile device not having the encryption processing function is the calling device is shown in FIG. This will be explained below with reference to it.

The device of this embodiment initially includes an encryptor 17-a and a decryptor 17-a.
-b is connected, and when detecting a call from the other party's device, the NCU 6 forms a DC loop on the transmission line 51 and responds. Then, the flow control unit 11 generates a pre-procedure signal from the control signal generation unit 2 to notify the calling side of the functions of its own device, frames it in the transmission data control circuit 4, and then sends it to the encoder 17-a. is encrypted, modulated by the modulation circuit 5, and transmitted as a procedure signal 111 to the calling side device via the transmission line 51 and the line network 50.

However, the calling side device is not equipped with an encryption function and cannot analyze this encrypted pre-procedure control signal. Therefore, no pre-procedure control signal is sent from the calling side. Therefore, in the device of this embodiment, when a significant signal is not received from the calling device even after a predetermined period of time has elapsed after transmitting the pre-procedure control signal 111, the switch circuits 16-a to 16-d are controlled. The encoder 17-a and the decoder 17-b are set to be separated from each other. From then on, this state is maintained and the mode is set in which no encryption processing is performed.

Thereafter, the flow control unit 11 on the called side outputs a pre-procedure control signal 113 that is not encrypted by the encoder 17-a, and transmits the function of its own device to the calling side device. The control signal analysis unit of the calling device can analyze this signal, and can learn the function of the called device from the analyzed control signal. Therefore, from now on, the desired image signal will be transmitted and received using the communication control procedure signals 113 to 119, which have the same signal contents as 123 to 129 in FIG. 3, which are not encrypted according to the normal 03 facsimile communication control procedure. Become.

The above explanation deals with the case where the calling side device transmits an image signal, but even in the case of so-called polling communication in which the called side device transmits an image signal according to instructions from the calling side, the present invention applies to all Can be applied.

Furthermore, in the above explanation, the encoder 17-a and the decoder 17-
b is built into a facsimile machine, but the present invention is not limited to the case where such a cryptographic processing function is built-in, and the present invention is not limited to the case where a completely different device equipped with a cryptographic processing function is installed in a normal facsimile machine. It is also applicable to a system that can be additionally connected to a facsimile machine. In this case, a switch circuit may be provided at the connection part of the facsimile machine or the connection part of the cryptographic processing device.

Furthermore, in the above explanation, when the other device does not have the cryptographic processing function, the encryptor 17-a and the decoder 17-b, which have the cryptographic processing function, are unconditionally disconnected. The present invention is not limited to the above example (i.e., when a significant signal is not received from the other party's device, the control waits for the operator's instruction input, and only when the operator inputs the instruction, the facsimile is sent without encryption). It may be possible to enable communication and to disconnect the communication path if no instruction is input.Furthermore, it may be controlled to disconnect the communication path unconditionally when an encrypted control signal is not received. good.

By controlling in this way, confidential information will not be accidentally leaked.Switching of these operation modes is performed by changing the content written to the RAM 13 from the operation unit 14. Facsimile communication is possible in each mode of encryption/non-encryption/encryption/non-encryption automatic switching according to the instructions.

As explained above, according to this embodiment, in facsimile communication connected to a public telephone line, a facsimile machine to which an encryption device is connected and a facsimile machine to which an encryption device is not connected can communicate with each other. It becomes possible to do so.

Furthermore, by providing a switch circuit in a facsimile to which an encryption processing device is connected, the encryption device and the facsimile device can be connected and disconnected only by electrical means without using physical means. Therefore, it is possible to easily communicate with either a facsimile device to which the encryption device is connected or a facsimile device to which the encryption device is not connected, and the range of communication is not limited.

[Effects of the Invention] As explained above, according to the present invention, it is possible to communicate with either a facsimile machine equipped with a cryptographic processing function or a facsimile machine without a cryptographic processing function without physically removing the cryptographic processing means. It becomes possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a facsimile apparatus in an embodiment of the present invention, and FIG. 2 is an explanatory diagram of communication procedures when the facsimile apparatus in this embodiment is a calling station and performs facsimile communication using encrypted signals. , FIG. 3 is an explanatory diagram of the communication procedure when the facsimile device in this embodiment is the calling station and the other party's device does not have an encryption processing function. Fig. 5 is a block diagram of a conventional facsimile machine. In the figure, l: reading section, 2: control signal generating section, 3:
...Switching circuit, 4...Transmission data control circuit, 5...
Modulation circuit, 6... NCU, 8... Demodulation circuit, 9...
- Reception data control circuit, 10... control signal analysis section, 1
1... Flow control section, 14... Operation section, 15...
Recording section, 16-a to d... switch circuit, 17-a.
... Encryptor, 17-b... Decoder, 5o... Public telephone line network, 51.52... Transmission line, 60... Facsimile device.

Claims (3)

[Claims] (1) A cryptographic processing means that encrypts transmitted data and decrypts the encrypted data, and either the cryptographic processing means is connected to encrypt/decrypt the transmitted and received data, or the cryptographic processing means is separated and transmitted. A facsimile apparatus comprising: a switch means for switching whether data is transmitted and received without being encrypted. (2) In the facsimile apparatus according to claim 1, the switch means is further controlled to connect the cryptographic processing means when communication is started, and when the control signal from the other party's device cannot be recognized, the cryptographic processing means is controlled by the switch means. A facsimile machine comprising control means for separating and maintaining that state thereafter. (3) The facsimile apparatus according to claim 2, further comprising prohibition means for prohibiting the control means from disconnecting the cryptographic processing means of the switch means when performing a transmission operation.