JPH01174068A - Image communication equipment - Google Patents

Abstract

PURPOSE:To attain cryptographic communication not easily decoded with simple and inexpensive constitution by splitting a picture minutely in the unit of lines at the transmission, imbedding the resulting picture into a random picture, sending a cryptographic picture and extracting the split pictures at the reception according to a changeover procedure. CONSTITUTION:The picture information is selected at the 1st and 2nd lines, random information is selected at the 3rd and 4th lines, and the pattern is repeated at an interval of 4-line period to obtain picture information including random information. The imbedded picture information is decoded into the original picture information by selecting the 1st and 2nd lines and excluding the 3rd and 4th lines and repeating the pattern at an interval of 4-line period. Thus, the picture is split minutely in the unit of lines and imbedded into a random picture to send a cryptographic picture destroyed apparently to be illegible from a picture transmitter 10. On the other hand, the original picture is decoded by extracting the said split pictures according to the switching procedure sent prior to the cryptographic picture at a picture receiver 40.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an image communication device equipped with an encryption function.

2. Description of the Related Art Some image communication devices such as facsimile devices are equipped with encryption functions to provide confidentiality. but,
This type of image communication device with an encryption function generally has a problem in that its configuration is complicated and expensive.

As an image communication device with encryption function that is easy to configure and inexpensive,
For example, there is a facsimile machine described in Japanese Patent Application Laid-Open No. 61-79377. This is done by inserting extra random data of a predetermined length after the EOL signal indicating the end of one line of image information on the transmitting side, and removing a predetermined amount of data following the EOL signal on the receiving side. If the length of the random data to be inserted is determined in advance, secret communication can be carried out only between specific devices.

Problems to be Solved by the Invention However, although this configuration has the advantage of being relatively simple and inexpensive, it has the problem of being easily deciphered.

The above problem arises for the following reasons.

In other words, the insertion position of the random data that randomizes the image information is fixed, and the insertion position is after the EOL code indicating the end of the line, so it is easily detected. This is because the length of the data is also a fixed amount determined in advance.

Furthermore, image information into which random data has been inserted cannot be properly received by a normal image communication device configured to receive regular image information.

This can easily serve as a clue for deciphering information, such as where the encryption process is being performed.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image communication device that can perform encrypted communication that is difficult to decrypt with a simple and inexpensive configuration.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention switches and selects image information and random information according to a predetermined switching procedure that minimizes one line to random information and random information. The above switching procedure is sent out before the random information input image information, and the receiving side receives the switching procedure sent before the random information input image information, and according to the received switching procedure, it transmits the switching procedure from the received image information. It has a configuration in which the original image information is reproduced by thinning out random information line by line.

Effect of the Invention With the above-described configuration, the present invention transmits an encrypted image that is apparently destroyed in an unreadable manner by dividing the image line by line and embedding it in a random image. , the original image is reproduced by following the switching procedure sent with the encrypted image and extracting the divided electric image embedded in the encrypted image, making it difficult to decode with a simple and inexpensive configuration. It becomes possible to perform encrypted communication.

Embodiment FIG. 1 shows a schematic configuration of an image communication apparatus according to an embodiment of the present invention.

The image communication device shown in the figure is configured as a facsimile device having an information compression function by encoding, and performs encrypted image communication between an image transmitting device 10 and an image receiving device 40.

First, the image transmitting device 10 will be explained.

The image transmitting device 10 includes a reading section 12, a random data generation section 14, an image information switching section 16, a compression section 18, a white line detection section 20, a line control section 22, a modem 24, a storage section 26,
It is composed of an input means 28, a control section 30, and the like.

The reading unit 12 reads an image of a document or the like line by line. The reading operation of this reading section 12 is performed by an image information switching section 16, which will be described later.
It is controlled in conjunction with the operation of.

The random data generator 14 generates random information representing a random image.

The image information switching unit 14 has two selection positions a and b. When it is switched to one of the positions a, image information from the reading section 12 is selected and output. Moreover, when it is switched to the other side, random information from the random data generating section 14 is output as pseudo image information. At this time, the reading section 12 enters a standby state in which the reading operation is temporarily stopped.

The image information switching unit 14 operates under the control of the control unit 30 and selects read image information and random image information according to a predetermined switching procedure in which one line is the minimum unit. This results in
To create and output random information input image information by mixing regular image information into random information. This random information input image information is treated as if it were regular image information read from the reading section 12.

The compression unit 18 encodes the random information input information for information compression.

The white line detection unit 20 detects whether the image information for one line represents completely white. This white line detection section 20 is provided to shorten the transmission time for sending the white line.

The line control unit 22 adds a FILL signal (blank filling signal) to the encoded image information so that the transmission time per line exceeds a predetermined minimum transmission time. The minimum transmission time is switched and set by the control section 30 based on the detection by the white detection section 20 and the like.

The modem 24 modulates the encoded image information in which the data length per line has been adjusted using the line control unit 22f, and sends the modulated image information to the communication line.

The storage unit 26 stores the exclamation procedure of the image information switching unit 16 as information. This switching procedure is variably set by the input means 28.

The control unit 30 is configured using a microcircuit-based general-purpose information processing device, so-called a microcomputer, and centrally controls each of the above-mentioned units.

This control section 30 also has the function of a control means for sending out the above-mentioned switching procedure before the above-mentioned random information and human information.

Next, the image receiving device 40 will be explained.

The image receiving device 40 includes a modem 42, a line control section 44,
extension section 46, white line detection section 48, rain information statement section 50,
It is composed of a recording section 52, a storage section 54, a control section 56, and the like.

The modem 42 demodulates image information from a received signal input via a communication line.

The line control unit 44 removes the FiLL signal included in the received image information.

The decompression unit 46 decodes the encoded received image information.

The white line detection unit 48 detects line image information in which one line is entirely white. The day line detection section 48 is provided to shorten the recording operation of the recording section 52. That is, when the recording section 52 is to record a white line, it is caused to only feed the recording paper without performing any recording operation. This aims to shorten the recording time.

The image information switching unit 50 has two selection positions c and d. When switched to the one position C side, composite image information from the decompression section 46 is transmitted to the recording section 52 side. When the user learns how to use it at position d, the decoded image information is not transmitted anywhere and is eliminated (
canceled).

The image information switching section 50 performs a switching operation using one line of image information as the minimum unit under the control of the control section 56.

The recording section 52 prints and records the image information obtained through the image information switching section 50 on a recording paper line by line.

The storage unit 54 stores the switching procedure of the image information switching unit 5o as information. The exclamation procedure is manually entered into the storage section 54 via the control section 56, which will be described later.

The control section 56 is configured using a microcomputer or the like, and centrally controls each section within the image transmitting device 40.

At the same time, when the random information human information is sent as image information to the control section 56, the control section 56 is provided with a specification for detecting the switching procedure sent from the transmitting side 1 from the received signal prior to the random information human information. The function of information detection means is added. The switching procedure detected by the function of the specific information detection means is stored in the storage section 54, and when the random person information is received, decoded and output from the decompression section 46, the switching procedure is stored in the image information switching section 54. It is used to control the switching operation.

Thereby, the image information switching section 5o functions as an image extraction means for thinning out random information line by line from the random information human information according to the switching procedure detected from the received signal. The original image information extracted by this image extracting means is input to the recording section 52 and is printed and recorded on the recording paper.

FIG. 2 partially shows an example of the data format of the random information human information.

In the example shown in the figure, image information is selected for the 1st and 2nd lines, random information is selected for the 3rd and 4th lines, and by repeating this pattern every 4 lines, regular image information can be obtained. Random information human information is obtained by mixing the information into random information. The random information human information obtained in this way is obtained by selecting the 1st and 2nd lines, excluding the 3rd and 4th lines, and repeating this pattern every 4 lines. is thinned out and reproduced to the original image information.

In this case, the above-mentioned repeating pattern, that is, the switching procedure is arbitrarily set depending on the density of image information and the like. For example, if the image density of the image information is high and detailed, a repeating pattern with a short cycle is set. In the opposite case, a repeating pattern with a long period is set. Further, it is preferable that the repeating pattern is complex rather than monotonous.

FIG. 3 partially shows an example of a communication control procedure in the image communication apparatus described above.

In the communication control procedure shown in the figure, in phase B, an NSF signal (non-standard equipment signal) is sent from the receiving side to the transmitting side.
When the Dis signal (digital identification signal) is sent, the sending side sends back the NSS signal (non-standard device signal corresponding to the NSF signal) and OCS signal (digital identification signal corresponding to 01S) to the receiving side. Ru. At this time, the above switching procedure is inserted into the FiF (Facsimile Information Field) in the NSS signal transmitted from the transmitting side to the receiving side.

As a result, the above switching procedure is sent to the receiving side prior to the image information.

After this, the transmitting side sends out a training signal and a TCP signal (training check signal), and the receiving side sends out a CFR signal (ready for reception signal), thereby determining the speed of the modem and performing phase matching.
The process moves to phase C in which an image signal, which is actual information, is transmitted.

In this phase C, random information input information created according to the previously sent switching procedure is transmitted from the transmitting side to the receiving side.

As described above, the image transmitting device 1o sends out an encrypted image that is apparently destroyed in an unreadable manner by dividing the m image into 5-in units and embedding it in a random image. be done.

On the other hand, on the image receiving device 4o side, the original image is reproduced by extracting the segmented image embedded in the encrypted image according to the switching procedure sent before the encrypted image.

This makes it possible to perform encrypted communication that is difficult to decrypt with a simple and inexpensive configuration.

In this case, the encrypted image, that is, the random information input information, is formally equivalent to the regular image information, so that it can be received even by a device that does not have an encryption function. However, since the received image has been encrypted to make it unreadable as described above, the recipient is likely to think that the encrypted image has been encrypted at the original document stage. At the very least, there is no clue as to at what stage the encryption process was performed, which is an advantage in making decoding even more difficult.

Effects of the Invention As is clear from the above description, the present invention creates random information input information on the transmitting side by switching and selecting image information and random information according to a predetermined switching procedure that minimizes one line. , the above switching procedure is sent before the random information input image information, and the receiving side receives the switching procedure sent before the random information input information, and according to the received switching procedure, random information is extracted from the received image information. By thinning out the original image information in line units, when transmitting, the image is divided into line units and embedded in a random image to send out an encrypted image that is apparently destroyed in an unreadable manner. While it is possible,
When received, the original image can be reproduced by following the switching procedure sent with the encrypted image and extracting the fragmented images embedded in the encrypted image, making it difficult to decode with a simple and inexpensive configuration. This has the effect that encrypted communication can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an image communication device according to an embodiment of the present invention, FIG. 2 is a diagram partially showing an example of the format of random information input information encrypted by the same device, and FIG. 3 is the above-mentioned example. FIG. 3 is a diagram partially showing an example of a communication control procedure by the device. 10... Image transmitting device, 12... Reading unit, 14
...Random data generation section, 16...
Image information switching unit, 18...Compression unit, 20...
・White line detection section, 22...line control section, 24
...Modem, 26...Storage section, 28...
・Manual means, 30... Control section, 40...
- Image receiving device, 42, modem, 44...line control unit, 46...expansion unit, 48...white line detection unit, 50...image information switching Department, 52...
...Recording section, 54...Storage section, 56...
・Control unit, L...Communication line.

Claims (3)

[Claims] (1) On the transmitting side, an image information switching means that creates random information input information by switching and selecting image information and random information according to a predetermined switching procedure in which one line is the minimum unit; The receiving side includes a specific information detection means for detecting a switching procedure sent before the random information input information, and a control means for transmitting the random information before the input image information, and a specific information detection means for detecting a switching procedure sent before the random information input information, and a control means for transmitting the random information from the received image information according to the detected switching procedure. An image communication device comprising an image extraction means for thinning out random image information line by line. (2) The image communication device according to claim 1, further comprising input means for variably setting the switching procedure. (3) The image communication device according to claim 1 or 2, further comprising a storage means for storing the received switching procedure.