KR20160070286A - Cloud based computing platform system for preserving privacy and method for providing location based service - Google Patents

Abstract

Disclosed is a technology which can protect privacy of a mobile terminal based on a cloud server and can provide a location-based service. A method for providing a location-based service, which is performed in a privacy protecting cloud server may comprise the steps of: receiving a request for a location-based service from a mobile terminal; requesting the location-based service from a location-based service (LBS) server; receiving all points of interest, corresponding to a region in which the location-based service is requested, from the location-based service server; determining a preset reference number of mobile terminals among mobile terminals located in the region to which the location-based service belongs; and providing a point of interest to each of the terminal, having requested the location-based service, and the reference number of mobile terminals.

Description

Technical Field [0001] The present invention relates to a privacy-protected cloud-based computing platform system and a method for providing the location-

Embodiments of the present invention relate to techniques for providing location based services based on mobile cloud servers.

Currently, mobile terminals such as smart phones are not only used as means for simple communication between individuals, but also become part of individual lives. For example, a mobile terminal is used to provide various types of location based services (LBS) such as play, convenience facilities, information, and the like. Applications such as Google and iPhone exist on-line, and in order to obtain useful services in such applications, most mobile terminals are faced with problems related to security, storage space, bandwidth, and battery life due to hardware capacity limitation . To solve these problems, studies are being conducted to integrate mobile terminals with cloud computing, which is called mobile cloud computing.

Mobile cloud computing is Internet-based computing, providing shared data, software, and information to other devices such as computers as needed. Cloud-based services include Infrastructure as a Service (IaaS), Data Storage as a Service (DaaS), CaaS, SecaaS, HaaS, , Service type software (SaaS), service type business (BaaS), and service type platform (PaaS). Cloud computing is being explored in many areas because of its benefits such as better performance, reasonable software costs, immediate updates, large storage space, device independence, improved data reliability, and improved document format compatibility. Mobile cloud computing provides the infrastructure for both data storage and data processing that occurs outside the mobile terminal.

The location-based service (LBS) refers to providing a variety of services to a mobile terminal using a geographical location of a mobile terminal, such as an accessory search, a route guidance, and a map service. In order to protect the privacy of users, the LBS has a limited service, and there are difficulties in providing the service. In order to provide the LBS service to the mobile terminal, location information of the mobile terminal must be collected. Such location information collection may infringe the privacy of the user having the mobile terminal.

For example, when the mobile terminal provides its location information to the LSB provider in order to receive the location-based service, the hacker (attacker) tracks the user's activity using the location information transmitted by the mobile terminal, It can be harassed. In addition to hackers, the LBS provider can also infer user's personal information by linking the locations visited by the user and maliciously exploit the inferred results. Most users want to be provided with various location-based services without disclosing personal information or location information in order to avoid privacy breaches.

Therefore, there is a need for a technique capable of providing location-based services while protecting the user's privacy.

An embodiment of the present invention is to provide a privacy-protected cloud-based computing platform system and a method of providing a location-based service that can provide a location-based service requested by a user while protecting user's privacy in a mobile cloud computing environment.

More particularly, the present invention relates to a communication security providing anonymity of a mobile terminal by providing communication between a mobile terminal and a cloud server using an Orbot, and a location-based service to a plurality of mobile terminals, So as to protect the privacy of the user.

A method for providing location-based services in a privacy-protected cloud server includes receiving a location-based service from a mobile terminal, requesting the location-based service from a location-based service (LBS) server, Based service, the method comprising the steps of: receiving all points of interest (POIs) corresponding to the requested area; determining mobile terminals of a predetermined reference number for the mobile terminals located in the area to which the location-based service belongs; And providing a point of interest to each of the terminals requesting the base service and the reference numbers of the mobile terminals.

According to an aspect, the step of providing the point of interest further comprises the step of providing points of interest received from the location-based service server based on the current location of each of the reference number of mobile terminals, the current location of the terminal requesting the location- Determining a nearest point of interest from each mobile terminal, and providing the determined point of interest to each mobile terminal.

According to another aspect, determining the closest point of interest may determine a point of interest (POI) located closest to the current location of each mobile terminal based on the Euclidian distance.

According to another aspect, the method may further include authenticating the mobile terminal requesting the location-based service.

According to another aspect of the present invention, the step of authenticating the mobile terminal comprises the steps of: requesting an International Mobile Station Identity (IMSI) granted to the mobile terminal; and transmitting the IMSI received from the mobile terminal to the database And authenticating the mobile terminal by checking whether the mobile terminal has been registered.

According to another aspect, the step of authenticating the mobile terminal may authenticate the mobile terminal using SHA-1 encryption.

According to another aspect, the reference number may be set so as to increase in proportion to a privacy ratio to be enhanced when the privacy of the mobile terminal is to be enhanced.

According to another aspect, the mobile terminal may discard a point of interest received from the privacy protection cloud server when the location-based service is not requested.

The privacy protection cloud server includes a service processing unit for receiving a location-based service from a mobile terminal and requesting the location-based service from a location-based service server (LBS) Based service; a mobile terminal determination unit for determining a predetermined number of mobile terminals for mobile terminals located in an area to which the location-based service belongs; And a point of interest provider that provides points of interest to the requested terminal and the reference number of mobile terminals, respectively.

According to an aspect of the present invention, the point-of-interest providing unit is configured to transmit the point-of-interest service to each of the points of interest received from the location-based service server based on the current position of each of the reference number of mobile stations, Determine the closest point of interest from the terminal, and provide the determined point of interest to each mobile terminal.

According to another aspect, the point of interest provider may determine a point of interest (POI) that is located closest to the current location of each mobile terminal based on the Euclidian distance.

According to another aspect, the mobile communication terminal may further include an authentication unit for authenticating the mobile terminal requesting the location-based service.

According to another aspect of the present invention, the authentication unit requests the International Mobile Station Identity (IMSI) assigned to the mobile terminal and confirms whether the IMSI received from the mobile terminal is already registered in the database Thereby authenticating the mobile terminal.

According to another aspect, the authentication unit can authenticate the mobile terminal using SHA-1 encryption.

According to another aspect, the mobile terminal can communicate with the cloud server using Orbot to guarantee anonymity of the mobile terminal.

A privacy-protected cloud-based computing platform system includes a mobile terminal that requests anonymously location-based service to a cloud server using Orbot, a mobile terminal that requests the location-based service, A cloud server that provides Points of Interest (POIs) to mobile terminals, and

And a location-based service server that searches all POIs corresponding to the area to which the location-based service requested by the cloud server belongs, and provides the recorded file with the browsed POI to the cloud server.

According to an aspect of the present invention, the cloud server can authenticate a mobile terminal requesting the location-based service using an International Mobile Station Identity (IMSI).

It is possible to provide location-based services requested by users while protecting user's privacy in a mobile cloud computing environment.

In addition to providing communication security that provides anonymity of a mobile terminal by providing communication between a mobile terminal and a cloud server using Orbot, it provides location-based services to a plurality of mobile terminals, It is possible to protect the privacy of the mobile terminal so that the mobile terminal is not exposed to the server.

1 is a diagram illustrating a schematic structure of a privacy-protected cloud-based computing platform system in an embodiment of the present invention.
2 is an exemplary diagram provided to illustrate the operation of configuring the location of each region using cloaking in one embodiment of the present invention.
3 is a flowchart illustrating an operation in which a cloud server provides a location-based service while assuring anonymity of a mobile terminal in an embodiment of the present invention.
Figure 4 is an illustration of an embodiment of the present invention. And a detailed configuration of the cloud server.
5 is a flowchart illustrating a detailed operation for providing a location-based service while protecting the privacy of a mobile terminal in an embodiment of the present invention.
FIGS. 6 to 9 are diagrams for explaining scenarios 1 to 4 according to an embodiment of the present invention.

The embodiments are intended to illustrate techniques for protecting privacy by providing anonymity of a user when providing location-based services in a mobile cloud computing environment. First, a mobile cloud computing platform and a location-based service will be briefly described to facilitate understanding of the embodiments.

In one embodiment of the invention, the Privacy Preserving Cloud Computing Platform (PPCCP) may have software and hardware capabilities. PPCCP using location based service (LBS) is based on untrusted cloud server, and cloud server and mobile terminal can block malicious user access by using International Mobile Station Identity (IMSI). In these embodiments, the cloud server may be an intermediary that prevents a user with a mobile terminal from being directly exposed to a location-based service (LBS) provider. For example, the following security requirements can be ensured so that users are not exposed to LBS providers.

(One) Privacy: An attacker such as a hacker can not know the user's location during the communication phase that a user performs to receive a location-based service (LBS).

(2) Prevention of excessive collection: The service provider can know only the appropriate range of user's location information.

(3) Authentication: The service provider can check whether the user's location is correct or not.

(4) Unforgeability: An attacker can not forge a user's location.

(5) Prevention of retransmission attacks: When a user's location information is authenticated and used for location-based services, the location-based service (LBS) provider does not reuse the user's location information without the user's approval.

Transformation, Private Information Retrieval, Cloaking / Anonymity, etc. may be used to ensure that the above security requirements are ensured.

A. Transformation

The change is to change the query in a secure way so that the server does not know the location of the user. There is a technique to apply encryption protocol and a technique to use geographic change. The former is a non-spatial change that provides a strong privacy by applying a cryptographic protocol, which requires a great deal of computationally and telecommunication cost. The latter includes spatial changes that determine the location of the user through geographic changes, including scaling, transformation, rotation, and the like.

For example, a framework called Space Twist is used to identify unauthenticated LBS servers. The space twist progressively requests the location of Points-Of-Interest (POI) according to the distance that the anchor point is away from the fake location near the query point, and receives the requested POI information. If the anchor point is selected too close to the query point, there is a difficulty in creating a comprehensive cloaking region. On the other hand, when the anchor point is selected too far, the communication cost and the computation cost are considerably increased.

B. Private Information Retrieval (PIR)

The PIR allows a user to send a query to the LBS server without exposing the location-based service request. In the case of PIR, it guarantees privacy to support spatial queries, but it is hardware dependent, security coprocessor space is limited, computational complexity is increased, and communication cost is increased.

C. Cloaking / Anonymity

The cloaking / anonymity technique creates K user groups to hide or obscure the exact location of a particular user from users of K nouns. The K users may actually be in the cloaking region, or they may be dummies. Creation of the cloaking region may be concentrated or depending on where the cloaking takes place, or may be distributed.

Centralized Cloacking is based on an authenticated server. For example, an authenticated server is a server used to protect a user's location and personally identifiable information, and may be an authenticated location anonymous person. Location Anonymity can be placed between the user and the LBS server to protect the user's precise location and personal information that is presented to the attacker. As such, when using the location anonymizer, the location anonymizer knows the location and personal information of all users, so it must be trustworthy. If the location anonymant fails to perform its function due to a failure or the like, the security provided to the user may be broken. In addition, when a user repeatedly requests a location-based service, a specific user among the K users can be exposed.

In the case of distributed cloaking, the user's location and movement route are hidden by sending multiple non-single queries to the location anonymous, but the server response rate slows down as the number of requests sent by the user increases. In addition, it may happen that a user request is ignored by suspecting an LBS attack. As such, depending on which dummies are selected, the user's actual information may or may not be easily exposed.

Collaborative cloaking creates a cloaking region by finding each user and nearby users with K users. If not enough users are found in the vicinity, the response speed is slowed as each request recipient repeatedly broadcasts around until it finds K users.

 As described above, there is a threat of communication threat and location privacy when using a location-based service (LBS), despite efforts to secure anonymity of a user having a mobile terminal based on a cloud server.

A communication threat is related to the anonymity of the user requesting the location-based service, which means that the eavesdropper or the LBS provider can not determine the identity of the person who created the message of the IP address. For example, a communication threat refers to the fact that, when a user requests a location-based service using WiFi, the actual location of the user can be tracked using the user's IP.

The location privacy threat may be related to the anonymity of the sender, and may be difficult to function properly due to the association with the location information obtained by observing the message creator. For example, location privacy can be divided into the following three categories.

First, as a limited space identification, it is assumed that the resident location belongs to exactly one person. For example, assuming that the LBS provider is honest and responds to processes and messages, the user identifier can be determined based on the received information and the real world information. If the attacker finds the location information of the user, it can find the location of the user's actual location. And, it is easy to find a resident using the phone book. Second, it is observation identification. Assuming that an attacker can know a previously transmitted message from one location, when the sender sends a new anonymous message, the attacker can locate the sender and eventually find the owner there. Third, a set of locations for the user, location tracking associated with the message, allows the attacker to know the user's activity record.

In the above communication and location privacy threat models, it can be assumed that there is a local eavesdropper monitoring the internet traffic between the user and the cloud server or the traffic between the cloud server and the LBS provider. However, in the present embodiments, it is assumed that the traffic does not think about a global eavesdropper capable of monitoring all traffic, even though it uses a proxy web site to hide the address. It also assumes that it does not take into account the mechanism used by an attacker to penetrate the user's mobile terminal and hack the customer's application and its Internet connection. In addition, we assume that we do not consider the use of mechanism to prevent trace anonymity. For example, mechanisms such as matching unnecessary anonymity requests with a particular service, requesting a specific local service sequence in a certain pattern that can be tracked by an attacker, and malicious users attempting to flood We assume that we can attack the proposed model.

Hereinafter, a computing platform system based on a privacy-protected cloud server and a method for providing a location-based service will be described in detail with reference to the drawings.

1 is a diagram illustrating a schematic structure of a privacy-protected cloud-based computing platform system in an embodiment of the present invention.

1, the privacy-protected cloud-based computing platform system 100 includes a mobile terminal 110 that requests location-based services, a mobile terminal 110 that verifies the location-based services requested by the verified mobile terminal 110, And a LBS server 130 for transmitting a POI corresponding to the requested location-based service.

Here, the mobile terminal 110 may be a smart phone, a tablet PC, or the like, and may refer to all terminals capable of accessing a web / mobile site related to a location-based service or installing and executing a service-dedicated application. The mobile terminal 110 can install and execute the location-based service application provided by the LBS server 130 or the cloud server 120 in order to receive the location-based service. Then, the mobile terminal 110 can execute the installed application and request the location-based service to the cloud server 120. The application may include a small database of area identifiers and a small amount of processing routines to locate the area where the user with the mobile terminal is currently located. The processing routine is for allowing the cloud server 120 to continuously recognize the current location of the user, and may be used to periodically check the Internet connection of the server at regular intervals. Based on the request of the cloud server 120, the processing routine may anonymously transmit the current location of the mobile terminal to the cloud server using the OBO.

The cloud server 120 may be an intermediary connecting the mobile terminal 110 and the location-based service (LBS) server 130. When the location-based service is provided, the cloud computing apparatus 120 may be used to utilize the computing resources of the cloud provided by the cloud including processing power, reliability, and scalability.

The embodiments are for explaining configurations for protecting the privacy of the mobile terminal 110 even if the cloud server 120 does not perform its function due to failure, error, or the like. As such, in order to protect the privacy of the mobile terminal 110, all communications used in the present embodiments may be based on AES-126 bit encryption. For example, the keys encrypted using the Diffie-Hellman key exchange between the mobile terminal 110 and the cloud server 120 may be shared with each other before the start of communication for the location-based service request. For example, the mobile terminal 110 may share the encrypted keys with the cloud server 120 at the time of communication establishment or application installation. In response to the location-based service request, the cloud server 120 can authenticate the mobile terminal 110 using the encrypted keys.

In addition, the mobile terminal 110 may perform a communication connection with the cloud server 120 by using an Orbot in order to provide a guarantee against the communication threat mentioned above. Here, Obob can represent free proxy software provided by Google Play for Android devices. Obot uses Tor to securely use the Internet by encrypting Internet traffic. For example, when the mobile terminal 110 requests a location-based service by installing a web browser supported by Orb, such as Orweb, the mobile terminal 110 can access the cloud (PPCCP) server 120 anonymously.

Then, the cloud server 120 requests the LBS server 130 to provide location-based services while assuring the anonymity of the mobile terminal 110 so that it is not possible to confirm which user (i.e., mobile terminal) has requested the location-based service .

For example, in order to ensure the anonymity of the mobile terminal 110, the cloud server 120 may divide the geographic space of the world into cloaking regions. Assuming that the entire world is made up of rectangular shaped regions of different sizes on a two-dimensional grid, one of those regions can be used as a cloaking region. Each region included in the grid can be identified by using the grid identifier. For example, referring to FIG. 2, the GPS coordinates 201 of one corner (upper left corner) of each area may be set as an identifier of the corresponding area. Referring to FIG. 2, when the Korean map is divided into cloaking regions, the grid can be depicted by rectangular regions of different sizes on the map and identifiers of the regions. Here, on a map, regions of various sizes can be divided into two-dimensional maps using Miller Cylindrical projection. The same point of interest (POI) distribution in each of the divided regions can be constructed in the database using the Hilbert space-filling curve.

LBS server 130 is an independent location-based service provider that can pre-build, manage, and maintain POI databases. The POI database has fields for areas, and the area field can be similar to a user application. And, the POI database may further include a region identifier table. For example, when a location-based service including a region identifier and a region name is requested from the cloud server 120, the LBS server 130 searches for a requested service in a specific region in the POI database, (txt) file. The LBS server 130 may transmit the text file to the cloud server 120. For example, the POI database can be pre-constructed and stored as shown in Table 1 below.

Region ID Service Name POI Detail 2014 Hospital KUMC, Ansan

Hereinafter, with reference to FIG. 3 and FIG. 4, a detailed operation of assuring the anonymity of the mobile terminal with respect to the LBS server by the cloud server will be described.

FIG. 3 is a flowchart illustrating an operation of providing a location-based service while ensuring anonymity of a mobile terminal in an exemplary embodiment of the present invention, and FIG. And a detailed configuration of the cloud server. 3, each of the steps 310 to 350 of providing a location-based service includes the service processing unit 410, the authentication unit 420, the interest point receiving unit 430, the mobile terminal determination unit 440, And an interest point providing unit 450.

In step 310, the authentication unit 420 may authenticate the mobile terminal 401 requesting the location-based service.

For example, the service processing unit 410 can receive a location-based service such as a hospital, a restaurant, a bus stop, and the like around the mobile terminal 401 through an application executed by the mobile terminal 401. At this time, the mobile terminal 401 encrypts the service name and the area identifier for requesting the location-based service using the shared key S _k encrypted using the Diffie-Hellman key exchange S _k (Service || Region ID)) to the cloud server 400. Then, the authentication unit 420 requests the mobile terminal 401 to authenticate the mobile terminal 401, and authenticates the mobile terminal 401 using the IMSI.

In step 320, when the authentication of the mobile terminal 401 is successful, the service processing unit 410 can request the LBS server 402 location-based service. For example, the service processing unit 410 may transmit the decoded service name (Service) and the region ID (Region ID) to the LBS server 402. Then, the LBS server 402 can search all the points of interest corresponding to the requested location-based service in the POI database and transmit it to the cloud server 400.

In step 330, the point of interest receiver 430 receives the point of interest from the LBS server 402 and the point of interest provider 450 can transmit the received point of interest to the mobile terminal 401.

In step 340, the mobile terminal determination unit 440 may determine K mobile terminals other than the request terminal so that the anonymity of the mobile terminal requesting the location-based service is guaranteed. For example, the mobile terminal determination unit 440 can arbitrarily select mobile terminals having a predetermined reference number K among a plurality of mobile terminals located in the requested area.

In step 350, the point of interest provider 450 may send a K point of interest to the determined K mobile terminals and the mobile terminal requesting the location based service. That is, K + 1 mobile terminals may be provided with points of interest.

At this time, the mobile terminal requesting the location-based service receives the POI from the cloud server 400 and provides location-based services such as a hospital location and a restaurant location. The K mobile terminals arbitrarily selected receive the POI (POIs) can be discarded.

By providing the POI to a plurality of mobile terminals in addition to the mobile terminal requesting the location-based service, the location of the mobile terminal requesting the location-based service is guaranteed to be anonymity for the LBS server or the mobile terminal so that the attacker can not know .

5 is a flowchart illustrating a detailed operation for providing a location-based service while protecting the privacy of a mobile terminal in an embodiment of the present invention. Each of the steps 501 to 514 of FIG. 5 includes the service processing unit 410, the authentication unit 420, the interest point receiving unit 430, the mobile terminal determination unit 440, and the interest point providing unit 450, Lt; / RTI > In the following description of each step of FIG. 4, a description overlapping with that shown in FIG. 3 will be omitted.

In step 501, the mobile terminal 520 can request a location-based service to the cloud (PPCCP) server 530 through a user interface provided by the installed application.

The location based service may include an encrypted service name and a region ID using the shared key S _k shared between the mobile terminal 520 and the cloud server 530.

At this time, the mobile terminal 520 can request a location-based service to the cloud server 530 using the ovot for ensuring anonymity.

In step 502, the service processing unit 410 may request the IMSI from the mobile terminal 520 to authenticate the mobile terminal requesting the location-based service. The cloud server 530 may previously store the IMSI of all users previously registered in the database to authenticate the mobile terminals.

In step 503, the mobile terminal 520 receiving the IMSI request may encrypt its IMSI using the SHA-1 cryptographic hash (SHA-1 (IMSI)). The mobile terminal 520 may encrypt the encrypted IMSI with the shared key S _k and transmit it to the cloud server S _k (SHA-1 (IMSI)). Communication between the mobile terminal and the cloud server is performed using the shared key based on the IMSI and the Diffie-Hellman encryption. By using the obt, not only the anonymity of the mobile terminal with respect to the cloud server is guaranteed, The anonymity of the mobile terminal can be assured from an attacker who eavesdrops on communication between mobile terminals.

In step 504, the service processing unit 410 may receive the IMSI of the mobile terminal. The authentication unit 420 can decrypt the received IMSI using the shared key and the SHA-1 cryptographic hash, and retrieve the IMSI corresponding to the decrypted IMSI from its database. At this time, if the IMSI of the mobile terminal 520 exists in the database, the authentication unit 420 can successfully authenticate the mobile terminal 520.

In step 505, the service processor 410 may request the LBS server 540 for the location-based service according to the successful authentication of the mobile terminal. For example, the service processing unit 410 may transmit a service name and a region ID included in the location-based service decoded in the LBS server 540. At this time, the service name and the area identifier may be encrypted using the shared key shared with the LBS server 540 and transmitted to the LBS server 540.

As described above, the cloud server 530 requests only the location-based service to the LBS server 540 without information on the mobile terminal 520, so that the LBS server 540 can not know which mobile terminal has requested the location-based service . Accordingly, the anonymity of the mobile terminal with respect to the LBS server is guaranteed, and even if there is an attacker who eavesdrops on communication between the cloud server and the LBS server, the attacker can not know which mobile terminal has requested the location-based service.

In step 506, the LBS server refers to the POI database to search for all POIs belonging to the requested location-based service. At this time, the LBS server 540 can decode the received service name and the area identifier using the shared key shared with the cloud server 530, and retrieve the decoded service name and the area identifier from the POI database.

For example, if a hospital search service in region A is requested, the LBS server 540 refers to the POI database and searches all hospitals (Service Names) in the region matching the requested region identifier (ID representing area A) You can search by point (POI).

In step 507, the LBS server 540 may record the retrieved POI in a text (txt) file.

In step 508, the LBS server 540 may send a text file containing all of the retrieved POIs to the cloud server 530. Then, the point-of-interest receiver 430 can receive the text file from the LBS server 540. [

In step 509, the mobile terminal determination unit 440 may determine any of the mobile terminals so that the location of the mobile terminal 520 requesting the location-based service is not exposed.

For example, the mobile terminal determination unit 440 may determine a predetermined number (K) of mobile terminals among the plurality of mobile terminals located in the requested area A based on the location-based service.

In operation 510, the mobile terminal determination unit 440 may transmit temporary values to the determined K mobile terminals 550. At this time, the mobile terminal determination unit 440 may transmit temporary values not only to the K mobile terminals 550 but also to the mobile terminal 520 requesting the location based service. Here, the temporary value may be an information value used for receiving the current location of K + 1 mobile stations.

For example, the mobile terminal determination unit 440 can determine K mobile terminals installed with applications providing location based services. Then, temporary values can be transmitted to the mobile stations through each installed application.

In step 511, the K + 1 mobile terminals receiving the provisional value may transmit their current location to the cloud server 530 through the installed application. For example, the installed application can find the current location of each terminal and transmit it to the cloud server 530. Here, the current position may include the GPS position coordinates of each of K + 1 mobile terminals.

In step 512, the point of interest provider 450 may determine the POI closest to each mobile terminal on a per-mobile-terminal basis, based on the current location of each mobile terminal received and the POI included in the text file.

For example, the point of interest provider 450 may determine the POI located closest to the current location of each terminal using the Euclidean distance.

In step 513, the point of interest provider 450 may transmit the POI determined for each terminal to the corresponding mobile terminal.

For example, the interest point providing unit 450 transmits the nearest hospital information from the mobile terminal 520 requesting the location-based service to the mobile terminal 520 and transmits the nearest hospital information from the terminal 1 To the terminal 1, and in the same way, the hospital information closest to the terminal 2 to the terminal K can be transmitted to the terminal 2 to the terminal K, respectively.

In step 514, K + 1 mobile terminals can receive the point of interest.

At this time, the mobile terminal 520 requesting the location-based service can receive the nearby hospital information requested by itself, and the K mobile terminals of the remaining dummies that have not requested the location-based service can discard the received POI have.

As described above, the privacy of the mobile terminal can be guaranteed by providing the POI to all of the K + 1 mobile terminals other than the one terminal requesting the location based service.

Accordingly, when the privacy of the mobile terminal is to be enhanced, the number of K can be increased. For example, the reference number K may be increased to be proportional to the rate of increase to enhance privacy.

5, the K mobile terminals are determined, and steps 509 through 511 for receiving the temporary value transmission and the current position to the K + 1 mobile terminals are performed after step 508 in which the text file including the POI is received The mobile terminal determination unit 440 may perform all the steps 509 through 511 before receiving the text file, and the cloud server 530 may perform steps 509 through 511 as described above. A text file may be received from the LBS server during execution.

For example, after the cloud server 530 has requested the location-based service to the LBS server 540 without waiting for the text file to be received, it immediately determines K mobile terminals, transmits a temporary value, It is possible to perform the operations of steps 509 to 511 for receiving. While the operations of steps 509 to 511 are performed in the cloud server 530, the LBS server 540 may search POIs in the POI database to generate a text file and transmit the text file to the cloud server. Accordingly, the cloud server 530 may receive the text file while the operations of steps 509 to 511 are performed, or may receive the text file after the execution is completed.

In addition, as described above, the cloud server can prevent the mobile terminal from being exposed to a malicious attacker using the SHA-1 cipher hash. After the cloud server has registered the IMSI encrypted with the SHA-1 hash into its database, the cloud server may store the hash of the new user in its database if the location based service is requested from the mobile terminal. The cloud server uses an interface to request a POI file to the LBS server, which interface may be provided through a computing module. That is, a text file in which a POI request and all POIs are recorded through the computing module can be received between the cloud server and the LBS server.

Thus, even if a malicious attacker continuously requests a plurality of location-based services to the cloud server by using the IMSI, for example, even if a denial of service (DoS) attack occurs, Identify the attacker's threats. For example, the cloud server can detect an attacker's threat by using n services and threshold values requested from the same mobile terminal for a predetermined time t (t / n <ξ). If a DOS attack is detected, the cloud server can block communication with the attacker.

Also, since the cloud server and the mobile terminal perform communication using the OBOT, the OP in the packet does not belong to the mobile terminal, so that the cloud server can not grasp the exact location of the mobile terminal.

 In addition, there is a trade-off relationship between privacy and computing costs, as can be increased privacy by increasing K mobile terminals. For example, as privacy increases, K increases, but as K increases, the POI to be calculated for each K mobile terminals may increase. That is, the process time for POI calculation may increase. Accordingly, the reference number K can be set to an appropriate value in consideration of the privacy and the process time. Conversely, if K is reduced, the process time can be shortened.

Hereinafter, how to protect the anonymity of the user provided by the location-based service providing method based on the privacy protection cloud server (PPCCP) described above will be described with reference to various scenarios as below.

Scenario 1: If communication with the cloud server in the mobile terminal is no longer secure,

As shown in FIG. 6, when an eavesdropper or an attacker interrupts the Orbot proxy mechanism, an eavesdropper or an attacker may receive an AES-128 bit cipher message. Even if the keys have lost their function, the eavesdropper or beneficiary will only benefit from getting the first message sent by the mobile terminal (or user) to the cloud server when the mechanism is completely stopped. This is because the information exchanged between the mobile terminal and the cloud server includes the service name and the user's IP. And even if the eavesdropper interprets another message, the eavesdropper can only get the hash of the nearest POI, which does not know which mobile terminal has requested the service.

Scenario 2: If the cloud (PPCCP) server is disconnected from the LBS server for secure communication,

As shown in FIG. 7, all messages between the cloud server and the LBS server can also be encrypted. At this time, when the key is exposed to the eavesdropper or the attacker, the eavesdropper or the attacker can only obtain the text file including the service name, the area identifier, and the POI list, and can not know the mobile terminal. Accordingly, the privacy of the mobile terminal is protected, so that the eavesdropper or the attacker can not attack the mobile terminal only with the obtained text file. In addition, the relationship between the cloud server and the LBS server can protect the privacy of the mobile terminal from semi-honest users who are curious to obtain additional information using a query.

Scenario 3: If the cloud server is not functioning due to failure, error, etc.,

Since the cloud server has only the hash of the IMSI of the mobile terminal and the hash of the area identification database, there is no room for the eavesdropper or the attacker to attack the mobile terminal using the cloud server that has lost the function. This is important when considering that the anonymity-based approaches of the other K must have complete data with the user's activities. As shown in FIG. 8, the cloud server according to the present embodiment does not provide any useful information to the attacker for the mobile terminal querying for location-based services. Moreover, the cloud server does not provide any useful information to the attacker for the other K mobile terminals in the protocol.

Scenario 4: If the cloud server itself is malicious,

The cloud (PPCCP) server may not be an intermediary between the LBS provider and the mobile terminal, or a trusted third party of the cloud server. Accordingly, the cloud server has only the IMSI of the mobile terminal and a general region identification database. Also, as each mobile terminal connected to the cloud (PPCCP) server communicates with the cloud server using Orbot, the cloud server can not know the actual IP of the mobile terminals requesting the service. The only information that the cloud server obtains last is the current locations of the K mobile terminals, which makes it impossible to link a specific location with a specific user. As shown in FIG. 9, since the cloud server calculates only the POI closest to the current location of each mobile terminal, it can not attack the mobile terminal requesting the service.

The system described above may be implemented with hardware components, software components, and / or a combination of hardware components and software components. For example, the components of the system and system described in the embodiments may be, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array ), A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI &gt; or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (10)

A method of providing location-based services performed on a privacy protected cloud server,
Receiving a location-based service from a mobile terminal;
Requesting the location-based service to a location-based service (LBS) server;
Receiving all points of interest (POIs) corresponding to the requested area from the location-based service server;
Determining a predetermined number of mobile terminals for mobile terminals located in an area to which the location-based service belongs; And
Providing a point of interest to each of the terminal requesting the location-based service and the reference number of mobile terminals
The method comprising the steps of: The method according to claim 1,
Wherein providing the point of interest comprises:
Determining a closest point of interest from each mobile terminal among the points of interest received from the location based service server based on the current location of each of the reference number of mobile terminals and the current location of the terminal requesting the location based service; And
Providing a determined point of interest to each mobile terminal
Wherein the location-based service providing method comprises: 3. The method of claim 2,
Wherein determining the closest point of interest comprises:
Wherein the point of interest (POI) located closest to the current location of each mobile terminal is determined based on the Euclidian distance. The method according to claim 1,
Authenticating the mobile terminal requesting the location-based service
Further comprising the step of: 5. The method of claim 4,
The step of authenticating the mobile terminal comprises:
Requesting an International Mobile Station Identity (IMSI) hash granted to the mobile terminal; And
Authenticating the mobile terminal by checking whether the IMSI hash received from the mobile terminal is already registered in the database
Wherein the location-based service providing method comprises: 5. The method of claim 4,
The step of authenticating the mobile terminal comprises:
Wherein the mobile terminal is authenticated using SHA-1 encryption. The method according to claim 1,
The reference number may be,
Wherein when the privacy of the mobile terminal is to be enhanced, the privacy ratio is increased in proportion to a privacy ratio to be enhanced. The method according to claim 1,
The mobile terminal,
And if the location-based service is not requested, discarding the point-of-interest received from the privacy-protected cloud server. A service processor for receiving a location-based service from a mobile terminal and requesting the location-based service from a location-based service (LBS) server;
A point of interest receiver for receiving all points of interest (POIs) corresponding to the requested area from the location-based service server;
A mobile terminal determining unit for determining a predetermined number of mobile terminals located in an area to which the location-based service belongs; And
Based service providing terminal and the reference number of mobile terminals,
Wherein the privacy protection server comprises: A mobile terminal for anonymously requesting a location server based on an orbot to a cloud server;
A cloud server for providing a POI to the mobile terminal and a predetermined reference number of mobile terminals so that the privacy of the mobile terminal requesting the location based service is protected; And
Based service server that searches for all points of interest (POIs) corresponding to the area to which the location-based service requested by the cloud server belongs, and provides the recorded file with the recorded interest point to the cloud server,
Based cloud computing platform system. &Lt; RTI ID = 0.0 &gt; A &lt; / RTI &gt;

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