JP2012068396A - Map data processing method, map data processing apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a map data processing method, map data processing apparatus and program capable of adjusting the time required for decrypting map data by changing a ratio of encrypting the map data in accordance with an importance degree of the map data or a utilization environment of a map data set.SOLUTION: A map data set includes map data comprised of area data divided for each area and collects a plurality of map data items with different reduction scales as one set. A map data processing method includes the steps of: determining, in the map data set, a ratio of area data to be encrypted and area data not to be encrypted in accordance with a reduction scale of the map data or a utilization environment of the map data set; determining the area data as a target of encryption on the basis of the ratio; and encrypting the area data determined as the target of encryption.

Description

  The present invention relates to a map data processing method, a map data processing device, and a program.

  The map data selling device stores map data on a storage medium such as a memory card for a fee. The storage medium storing the map data is used in an in-vehicle navigation device, and the navigation device provides route guidance based on the map data. The map data stored in the storage medium can be copied to another storage medium, and the navigation apparatus can provide route guidance based on the copied map data as long as it does not cope with unauthorized copying.

  Therefore, in order to suppress unauthorized copying of map data to another storage medium, the map data is encrypted by the map data sales apparatus, and the map data sales apparatus stores the encrypted map data in the storage medium. In Patent Document 1, only a part of map data is encrypted, and map data partially encrypted is stored in a storage medium. As a result, the time required for the navigation device to decrypt can be shortened compared to the case where the entire map data is encrypted.

JP 2003-131564 A

  In recent years, the use of map data has expanded, and in addition to personal computers and navigation devices, map data has also been used in various portable terminals with different calculation processing capabilities. If rapid data processing is required, the entire map data encrypted is not appropriate because it takes time to decrypt.

  In Patent Document 1, the portion of map data to be encrypted is a region containing important information as map data, such as a region where roads are dense, a region where facilities are dense, and a main road. Therefore, the data to be encrypted depends on the contents of the map data, and the amount of data to be encrypted cannot be adjusted. For example, the ratio of the encrypted data to the entire map data cannot be changed according to the use of the map data such as the calculation processing capability of the device that decrypts the map data and how much real-time performance is required.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to determine the ratio of map data encryption according to the importance of the map data or the use environment of the map data set. It is an object of the present invention to provide a new and improved map data processing method, map data processing device, and program capable of changing and adjusting the time required for decoding map data.

  In order to solve the above-described problem, according to one aspect of the present invention, in a map data set including map data composed of area data divided for each region, and a plurality of map data having different scales are combined into one set. In accordance with the scale of the map data or the use environment of the map data set, the step of determining the ratio of the area data to be encrypted and the area data not to be encrypted and the area data to be encrypted are determined based on the ratio. There is provided a map data processing method comprising the steps of: encrypting area data determined to be encrypted.

  An area on the map may further include a step of determining area data to be encrypted so that at least one map data among a plurality of map data in the map data set is encrypted.

  The method may further include a step of determining area data to be encrypted so that the area data to be encrypted and the area data not to be encrypted are arranged adjacent to each other.

  In order to solve the above problems, according to another aspect of the present invention, a map including map data composed of area data divided for each region, and a plurality of map data having different scales is combined into one set. In the data set, according to the scale of the map data or the use environment of the map data set, a ratio determining unit that determines the ratio of the area data to be encrypted and the area data not to be encrypted, and the encryption target based on the ratio There is provided a map data processing apparatus having an object determining unit that determines area data to be encrypted and an encryption unit that encrypts area data determined to be encrypted.

  In order to solve the above problems, according to another aspect of the present invention, a map including map data composed of area data divided for each region, and a plurality of map data having different scales is combined into one set. In the data set, a step of determining a ratio of area data to be encrypted and area data not to be encrypted according to the scale of the map data or the use environment of the map data set, and area data to be encrypted based on the ratio And a program for causing a computer to execute the step of encrypting the area data determined to be encrypted.

  As described above, according to the present invention, according to the importance of the map data or the use environment of the map data set, the ratio of the map data to be encrypted is changed to adjust the time required for decoding the map data. Can do.

1 is an overall configuration diagram showing a map display system according to an embodiment of the present invention. It is a block diagram which shows the portable terminal (camera apparatus) shown in FIG. It is explanatory drawing which shows the division | segmentation method of a map image. It is a figure which shows the structural example of map data. It is a flowchart which shows operation | movement of the program which CPU of the portable terminal shown in FIG. 2 performs. It is a figure which shows the map for demonstrating the method to encrypt a part of map data. It is a figure which shows the map for demonstrating the method to encrypt a part of map data. It is a figure which shows the example of a model of map data. It is a figure which shows the example of a model of map data. It is a flowchart which shows the setting operation | movement of the encryption area | region of map data, and a non-encryption area | region. It is a figure which shows the modeled map data for demonstrating the setting method of the encryption area and non-encryption area | region of map data. It is a figure which shows the modeled map data for demonstrating the setting method of the encryption area and non-encryption area | region of map data. It is a flowchart which shows the setting operation | movement of the encryption area | region of map data, and a non-encryption area | region. It is a figure which shows the modeled map data for demonstrating the setting method of the encryption area and non-encryption area | region of map data. It is a figure which shows the modeled map data for demonstrating the setting method of the encryption area and non-encryption area | region of map data.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

The description will be made in the following order.
1. 1. Overall configuration of map display system 2. About map data 3. Operation of camera device Encryption processing method

<1. Overall configuration of map display system>
Hereinafter, an embodiment of a map data processing method including a map data encryption method according to an embodiment of the present invention will be described with reference to the drawings.

  The overall configuration of the map display system shown in FIG. 1 includes a camera device 10 as a portable terminal owned by an individual, and a memory card 20 that is a semiconductor storage medium. The memory card 20 is a storage medium that can read and write map data and can be inserted into and removed from an electronic device such as the camera device 10. The memory card 20 stores map data, for example, for a fee by a map data sales device. The map data stored in the memory card 20 is encrypted by a map data selling apparatus by a method described later. Encryption by the map data sales apparatus is executed by a computer having a CPU and a memory.

  As shown in FIG. 2, the camera apparatus 10 includes a microcomputer 14 as a main component. The microcomputer 14 includes a CPU 14a, a ROM 14b, a RAM 14c, and an input / output interface 14d connected to each other by a bus. The CPU 14a is configured to execute the program stored in the ROM 14b while utilizing the data storage function of the RAM 14c.

  The camera device 10 also includes an operation switch unit 11, a display device 12, a read / write device 13, and a GPS device 15 connected to the input / output interface 14d so that signals can be exchanged with the microcomputer 14. Consists of.

  The operation switch unit 11 includes a plurality of switches and is operated by a user. By operating the operation switch unit 11, for example, input information such as latitude / longitude, address, and scale can be input to the microcomputer 14.

  The display device 12 includes a display (not shown), and displays necessary map information in accordance with an instruction signal from the microcomputer 11. The read / write device 13 includes a memory card 20 interface (not shown), and can read and write data in the memory card 20 inserted in accordance with an instruction from the microcomputer 14.

  The GPS device 15 receives a GPS signal from a GPS satellite (not shown), specifies the position of the own device by the received GPS signal every predetermined time, and transmits data related to the specified position to the microcomputer 14.

  The camera device 10 having the above configuration includes the encrypted map data in the inserted memory card 20, the user input information obtained from the operation switch unit 11, and the position of the own device obtained from the GPS device 15. Based on the above, the corresponding map data is read out, and after the read map data is decoded, the map is output to the display device 12.

<2. About map data>
Next, map data handled by the map display system will be described.
As shown in the map image dividing method of FIG. 3, the map image is divided into a plurality of regions. The divided individual areas are managed in the map data 300 as area data 330. Specifically, as shown in the configuration of the map data 300 in FIG. 4, the map data 300 includes management data 310, actual data 320, and the like. The management data 310 includes index information of the actual data 320 and the like. The actual data 320 is composed of a plurality of encrypted area data 330. The area data 330 is geographic data within a specific latitude / longitude. The memory card 20 stores a plurality of map data 300 having different scales. In this specification, a collection of a plurality of map data 300 having different scales is also referred to as a map data set. FIG. 4 shows one map data 300 in the map data set.

<3. Operation of camera device>
Next, the operation of the camera device will be described. Here, the flow of a program for processing the map data 300 stored in the memory card 20 by the CPU 14a of the microcomputer 14 and outputting it to the display device 12 will be described with reference to the flowchart of FIG. FIG. 5 is a flowchart showing the operation of the program executed by the CPU of the mobile terminal shown in FIG.

  In step 101, the microcomputer 14 receives the position data (latitude / longitude) obtained from the GPS device 15, the scale, etc. as input information. The CPU 14a specifies the map data 300 that matches the input information from the plurality of map data 300 stored in the memory card 20. In step 102, the management data 310 of the specified map data 300 is read from the memory card 20 into the RAM 14c.

  In the next step 103, the adapted area data 330 is specified from the actual data 320 based on the user input information obtained from the operation switch unit 11, the spec information of the camera device 10 such as the screen size, and the management data 310. . The microcomputer 14 specifies the requested area data 330 based on the index information of the management data 310. Then, the identified area data 330 is decoded on the RAM 14c, and in step 104, the map data is output to the display device 12 to display the map.

  In addition, this invention is not limited to the said embodiment, A various modification can be employ | adopted within the scope of the present invention. For example, in the above embodiment, the camera device 10 processes map data and displays a map, but the present invention is applicable to all terminals having a portable display screen.

<4. Encryption processing method>
Next, an encryption processing method in the map data sales apparatus will be described.
As will be described later, in this embodiment, whether to encrypt or unencrypt is specified in units of area data 330 in the map data 300. In addition, the feature is that there are a plurality of types of map data at the same position (latitude / longitude) for each scale. Examples of map data encryption are shown in FIGS. 6 shows a map with a small scale and displaying a wide range, and FIG. 7 shows a map with a large scale and displaying a narrow range compared to FIG.

  In this example, the map data 500 when the scale shown in FIG. 6 is small has an encryption ratio of 1/4, and the map data 510 when the scale shown in FIG. 7 is large is 1/2. Thus, an encryption method is conceivable in which the ratio of the encryption area is changed depending on the importance (scale, etc.) of the map data. A map with a larger scale has more detailed map contents and is more important as map data. Therefore, when deciding the amount of encryption, decide to increase the amount of encryption for map data with a larger scale. Also good.

  Further, when determining the ratio of area data to be encrypted and area data not to be encrypted, not only the importance (scale, etc.) of the map data but also the usage environment of the map data set, that is, the map data is decrypted and displayed. The ratio of the area data to be encrypted and the area data not to be encrypted may be determined according to the calculation processing capability of the terminal and the importance of the real-time property. Further, the ratio of the area data to be encrypted and the area data not to be encrypted may be determined according to the user's request for data protection such as a map data sales company and the use of the application for displaying the map. If the ratio between the area data to be encrypted and the area data not to be encrypted is determined, the area data to be encrypted is determined according to the ratio.

  The area data to be encrypted may be determined so that the area data to be encrypted and the area data not to be encrypted are arranged adjacent to each other. As a result, when the terminal decodes the map data for display, the area data that needs to be decoded and the area data that does not need to be decoded are alternately subject to decoding processing, so that the processing at the terminal can be made uniform. The processing load on the terminal can be reduced. Similarly, if the area data to be encrypted is determined so that the area data to be encrypted and the area data not to be encrypted are equally arranged in the map data, the processing in the terminal can be made equal. The processing load on the terminal can be reduced.

  In the map data selling apparatus, after the area data to be encrypted is determined, the area data determined to be encrypted is encrypted.

  By the way, although the above-described encryption method leads to an increase in the speed of the decryption process, there may be a region on the map that is not encrypted at all in any of the map data of a plurality of map data having different scales. In other words, a certain area on the map may be displayed at all scales. Therefore, there is a problem as a method for suppressing unauthorized copying of map data.

  Therefore, as shown in FIGS. 11, 12, 14, and 15, not only the ratio of the encryption area but also the arrangement of the encryption area and the non-encryption area in a plurality of map data having different scales are considered. That is, the area data to be encrypted is determined so that a certain area on the map is encrypted in at least one map data among a plurality of map data of the map data set.

  Specifically, if an area in map data with a small scale is an unencrypted area, the map data set is encrypted so that the area is always encrypted with any of the map data with a larger scale ratio. Process. As a result, it is possible to adjust the trade-off between the decryption processing speed and security while ensuring the minimum data security against unauthorized copying.

  A description will be given of an encryption method for processing so that there is always no unencrypted area over a plurality of scales.

  As shown in FIG. 8, a plurality of map data having different scales are hierarchically configured, and the map data of each layer (layer) is composed of a plurality of area data as described above.

  The relationship between map data having different scales can be expressed by modeling in a tree form as shown in FIG. If the area data of the map data of a certain layer is i, the area data of the layer one layer lower in scale than the layer including the area data i is referred to as Parent (i), and the scale is larger than the layer including the area data i 1 The area data group in the layer below is referred to as Children (i). Further, among the layers including the area data i, an area data group other than the area data i is referred to as Brokers (i). When a map is displayed based on the area data i, when the user operates to reduce the scale of the map, the map based on Parent (i) is displayed. On the other hand, when the user operates to increase the scale of the map, a map based on any one area data of Children (i) is displayed.

  The encryption method for processing so that there is always no unencrypted area across multiple scales is as follows: (1) Among all layers with different scales, a certain area is encrypted with at least one of the layers And (2) among all layers with different scales, a certain area is encrypted with at least one of the layers, and the encrypted areas are uniformly arranged in each layer. There is a way to do it.

  First, (1) an encryption method for encrypting a certain area in at least one of all layers having different scales will be described.

  Examples of map data encrypted by this method are shown in FIGS. In FIG. 11 and FIG. 12, it is assumed that the map data is composed of three layers. As shown in FIG. 11, if encryption is performed with the area data of the uppermost layer, encryption is unnecessary for all area data in the lower layer corresponding to the area data of the uppermost layer. Also, as shown in FIG. 12, for the area encrypted with the area data of the second layer from the top, the area data of the third layer from the top does not need to be encrypted. On the other hand, for the area that is not encrypted with the area data of the uppermost layer and the second layer from the top, the area data of the third layer from the top needs to be encrypted. In the case of map data composed of four or more layers, it can be similarly encrypted.

The encryption amount is determined in accordance with the encryption strength (step S111).
Next, the encryption candidate group j is set to the area data group of the smallest scale layer (step S112). Then, it is determined whether or not the encryption candidate group j (the area data group of the layer with the smallest scale) includes area data i that has not yet been determined to be encrypted or unencrypted (step S113). . If there is area data i for which encryption or non-encryption has not been determined, the area data i is acquired (step S114). Next, it is determined whether or not there is an area data group Children (i) of a layer one layer lower in scale than the layer including the area data i (step S115). In the case of the layer with the smallest scale, since Children (i) exists, encryption or non-encryption of the area data i is next determined from the encryption amount determined in step S111 (step S116). Thereby, the area data i is determined to be either encrypted or non-encrypted.

  If it is determined that the area data i is to be encrypted (step S118), the process returns to step S113, and encryption or non-encryption is determined for other area data of the encryption candidate group j. On the other hand, if it is determined that the area data i is not encrypted (step S118), the area data group of the layer one layer lower in scale than the minimum scale layer is set as Children (i) for the encryption candidate group j. To do. Then, returning to step S113, encryption or non-encryption is determined for the area data of the newly set encryption candidate group j.

  The same processing is performed for a layer below the area data group of the smallest scale layer. That is, if certain area data i is not encrypted in step S118, encryption or non-encryption is determined in a layer lower than that layer. If a certain area data i is encrypted, it is encrypted in at least one of all layers having different scales in that area. Therefore, in step S118, the encryption candidate group j is moved down one layer. The layer area data may not be set in the encryption candidate group j. If the above processing is repeated and the area data i of the encryption candidate group j is the lowest layer, it is determined in step S115 that there is no area data group Children (i) of the layer one layer below. Data i is encrypted (step S117). As a result, even if encryption is not performed at all in layers above the lowest layer, encryption is performed in at least one layer among all layers having different scales.

  In step S113, when it is determined that there is no undecided area for encryption in the encryption candidate group j and there is no area data for a layer on one layer (step S119), that is, When the layer including the encryption candidate group j is the top layer, the process ends. On the other hand, when the layer including the encryption candidate group j is not the top layer (step S119), the area data Brothers (Parent (i) other than the area data Parent (i) of the layer above the layer including the encryption candidate group j is included. )) Is set as a new encryption candidate group j, and the process returns to step S113.

  Next, (2) among all layers with different scales, a certain area is encrypted by at least one of the layers, and the encryption area is uniformly arranged in each layer. The method of making it will be described.

  Examples of map data encrypted by this method are shown in FIGS. 14 and 15, map data is assumed to be composed of three layers. In the example of FIG. 14, only the uppermost layer is encrypted, the uppermost layer is encrypted in the second layer from the top, and the uppermost layer is encrypted in the third layer from the top. There is an area. A certain area is encrypted in any one layer, and the encrypted areas are uniformly arranged in the same layer. In the example of FIG. 15, the area encrypted in the second and third layers from the top, the area encrypted only in the second layer from the top, and the area encrypted only in the third layer from the top Exists. A certain area is encrypted in any one layer, and the encrypted areas are uniformly arranged in the same layer.

The encryption amount is determined in accordance with the encryption strength (step S211).
Next, the encryption candidate group j is set to the area data group of the smallest scale layer (step S212). Then, it is determined whether or not the encryption candidate group j (the area data group of the layer with the smallest scale) includes the area data i that has not yet been determined to be encrypted or unencrypted (step S213). . If there is area data i for which encryption or non-encryption is not determined, the area data i is acquired (step S214).

  Then, encryption or non-encryption of the area data i is determined from the encryption amount determined in step S211 (step S215). Thereby, the area data i is determined to be either encrypted or non-encrypted. Thereafter, it is determined whether or not there is an area data group Children (i) of a layer one layer lower in scale than the layer including the area data i (step S216). In the case of the layer with the smallest scale, since Children (i) exists, Children (i) is set as a new encryption candidate group j, and the process returns to Step S213 to encrypt the remaining area data i. Or it decides whether it makes non-encryption.

  If it is determined in step S216 that Children (i) does not exist, the layer including the area data i is the lowest layer, and the process proceeds to step S217. Then, it is determined whether or not Parent (i) exists (step S217). Since the layer including the area data i is the lowest layer, since Parent (i) exists, the process proceeds to step S213. After returning to step S213, encryption or non-encryption is determined for other area data of the encryption candidate group j. The above processing is repeated, and in step S213, there is no area data i that has not yet been determined to be encrypted or unencrypted in the encryption candidate group j (area data group of the smallest scale layer). When it is determined that the area data i of the encryption candidate group j is the uppermost layer (Step S 213), it is determined that Parent (i) does not exist (Step S 218). To do.

  On the other hand, when the Parent (i) of the area data i of the encryption candidate group j exists (step S218), the process proceeds to step S219. Then, it is determined whether or not the area data i or all the children (i) are encrypted (step S219). If the area data i or all Children (i) is encrypted, it is encrypted in at least one layer among all layers having different scales. If the area data i or all Children (i) are not encrypted, Parent (i) is encrypted (step S220). As a result, encryption is performed in at least one layer among all layers having different scales. After step S219 and step S220, area data Brokers (Parent (i)) other than area data Parent (i) above the layer including encryption candidate group j is set as a new encryption candidate group j. Return to step S213.

  By the encryption process, the map data set is encrypted so that there is not always an unencrypted area over a plurality of scales.

  As described above, according to the present embodiment, the area to be encrypted or unencrypted is determined for each area data. At that time, the ratio of the map data to be encrypted depends on the importance of the map data (scale, etc.), the demand for data protection of the map data sales company, the calculation processing capacity of the device, the situation of using the map data (real time is important The encryption strength and the decryption calculation speed can be flexibly adjusted by changing according to various requirements such as whether or not. Further, by combining an encryption method in which an unencrypted area does not always exist across a plurality of maps with different scales, the data security can be improved.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Camera apparatus 11 Operation switch part 12 Display apparatus 13 Read / write apparatus 14 Microcomputer 14a CPU
14b ROM
14c RAM
14d Input / output interface 15 GPS device 20 Memory card

Claims (5)

In a map data set comprising map data composed of area data divided for each area and a plurality of map data having different scales as one set, depending on the scale of the map data or the use environment of the map data set Determining the ratio of the area data to be encrypted and the area data not to be encrypted;
Determining the area data to be encrypted based on the ratio;
Encrypting the area data determined to be encrypted;
A map data processing method comprising:   An area on the map further includes the step of determining the area data to be encrypted so as to be encrypted in at least one of the plurality of map data of the map data set. The map data processing method according to claim 1.   The map data according to claim 1, further comprising a step of determining the area data to be encrypted so that the area data to be encrypted and the area data not to be encrypted are arranged adjacent to each other. Processing method. In a map data set comprising map data composed of area data divided for each area and a plurality of map data having different scales as one set, depending on the scale of the map data or the use environment of the map data set A ratio determining unit for determining a ratio of the area data to be encrypted and the area data not to be encrypted;
A target determining unit that determines the area data to be encrypted based on the ratio;
An encryption unit for encrypting the area data determined to be encrypted;
A map data processing apparatus. In a map data set comprising map data composed of area data divided for each area and a plurality of map data having different scales as one set, depending on the scale of the map data or the use environment of the map data set Determining the ratio of the area data to be encrypted and the area data not to be encrypted,
Determining the area data to be encrypted based on the ratio;
A program for causing a computer to execute the step of encrypting the area data determined to be encrypted.

Images