CN109688545A

CN109688545A - Group's K-NN search method, first terminal, second terminal and server

Info

Publication number: CN109688545A
Application number: CN201811340260.8A
Authority: CN
Inventors: 陈红; 李翠平; 吴云乘; 郭若杨; 赵丹; 梁文娟; 吴垚
Original assignee: Renmin University of China
Current assignee: Renmin University of China
Priority date: 2018-11-12
Filing date: 2018-11-12
Publication date: 2019-04-26
Anticipated expiration: 2038-11-12
Also published as: CN109688545B

Abstract

The present invention provides a kind of group's K-NN search method, first terminal, second terminal and server, comprising: position arrangement information is sent to second terminal；Gathered by the actual position of first terminal and with the associated false position grouping of the actual position of the first terminal at first position according to the position arrangement information；Encryption indication information is generated according to the position arrangement information；Interest point set is generated according to the instruction information of user's input；The first position set, the encryption indication information and the interest point set are sent to server, so that the server is gathered according to the interest point set, first position set, the encryption indication information and the second position received from the second terminal, target query result is generated.Group's K-NN search method provided by the invention, improves secret protection ability.

Description

Group's K-NN search method, first terminal, second terminal and server

Technical field

The present invention relates to position positioning field more particularly to a kind of group's K-NN search method, first terminal, second eventually End and server.

Background technique

It is various with increasingly mature and Intelligent mobile equipment the extensive use of wireless communication technique and location technology Location-based service application has obtained development at full speed and has popularized.Wherein, group's K-NN search allows one group of user to utilize them Location information initiate to inquire jointly, to obtain interest point information as query result, so that point of interest is to the poly- of this group of user Collection distance is minimum.Group's K-NN search can be applied in multiple scenes, such as resource allocation, the troops are assembling, weather forecast. With the development of group's K-NN search technology, secret protection during group's K-NN search is increasingly paid close attention to.

Existing group K-NN search method, terminal to server send location information when, by the true of user Position and the random vacation position that generates form location sets, location sets are then sent to server, to prevent server can To directly acquire customer position information.

However, existing group K-NN search method, initiates multiple group arest neighbors in the same position when terminal and looks into When inquiry, server can appearance position in location sets that terminal is repeatedly sent is identical and content also identical position pushes away The actual position information for user is surveyed, the probability of actual position leakage is larger, protects the ability of privacy of user not high.

Summary of the invention

The present invention provides a kind of group's K-NN search method, first terminal, second terminal and server, to improve privacy Protective capability.

First aspect of the present invention provides a kind of group's K-NN search method, comprising:

Position arrangement information is sent to second terminal, so that the second terminal is according to the position arrangement information by institute It states the actual position of second terminal and gathers with the associated false position grouping of the actual position of the second terminal at the second position；

It is closed according to the position arrangement information by the actual position of first terminal and with the actual position of the first terminal The false position grouping of connection is gathered at first position；

Encryption indication information is generated according to the position arrangement information, the encryption indication information is for cryptographically referring to Show the actual position of position and the second terminal of the actual position of the first terminal in the set of the first position Position in the set of the second position；

Interest point set is generated according to the instruction information of user's input；

The first position set, the encryption indication information and the interest point set are sent to server, so that institute Server is stated according to the interest point set, first position set, the encryption indication information and from the second terminal The second position set received, generates target query result.

Optionally, the first position set, the encryption indication information and the interest are sent to server described After point set, further includes:

Receive the target query result that server is sent；

The target query result is decrypted, destination address is obtained；

The destination address is sent to the second terminal.

Optionally, the position arrangement information is position permutation matrix；

It is described according to the position arrangement information by the actual position of first terminal and with the true position of the first terminal Associated false position grouping is set to gather at first position, comprising:

It detects the actual position of the first terminal and private key is generated according to the actual position of the first terminal and position The false position of multiple first terminals is generated, the position generates private key and is used to for actual position and false position being associated；

According to the genesis sequence of the false position of the first terminal, by the actual position of the first terminal and described first Terminal vacation position is sequentially placed into the first reference set；

According to the position permutation matrix, first reference set is converted, generates the first position set.

The second aspect of the present invention provides a kind of group's K-NN search method, comprising:

Receive the position arrangement information that first terminal is sent；

It is closed according to the position arrangement information by the actual position of second terminal and with the actual position of the second terminal The false position grouping of connection is gathered at the second position；

It sends the second position to server to gather, so that the server is according to the interest received from first terminal Point set, first position set, encryption indication information and second position set generate target query as a result, the point of interest Set is described according to user's instruction generation, and the first position set is according to the position arrangement information by described first The actual position of terminal and with the associated false position grouping of the actual position of the first terminal at, the encryption indication information It is to be generated according to the position arrangement information, the encryption indication information is for encrypting the true position for indicating the first terminal Set position of the actual position of the position and second terminal in the first position is gathered in the set of the second position It sets.

Optionally, after the second position set to server transmission, further includes:

The destination address that the first terminal is sent is received, the destination address is to receive server by the first terminal Simultaneously generation is decrypted to the target query result in the target query result of transmission.

It is described according to the position arrangement information by the actual position of second terminal and with the true position of the second terminal Associated false position grouping is set to gather at the second position, comprising:

It detects the actual position of the second terminal and private key is generated according to the actual position of the second terminal and position The false position of multiple second terminals is generated, the position generates private key and is used to for actual position and false position being associated；

According to the genesis sequence of the false position of the second terminal, by the actual position of the second terminal and described second Terminal vacation position is sequentially placed into the second reference set；

According to the position permutation matrix, second reference set is converted, generates the second position set.

The third aspect of the present invention provides a kind of group's K-NN search method, comprising:

Receive interest point set, first position set and encryption indication information that first terminal is sent, the interest point set Conjunction is to indicate to generate according to user, and the first position set is according to the position arrangement information by the first terminal Actual position and with the associated false position grouping of the actual position of the first terminal at, the encryption indication information is basis What the position arrangement information generated, the encryption indication information is for encrypting the actual position for indicating the first terminal in institute State position of the actual position of the position and second terminal in the set of first position in the set of the second position；

The second position set that at least one described second terminal is sent is received, at least one second position set is obtained, Second position set be by the second terminal actual position and with the associated vacation of actual position of the second terminal Position grouping at；

According at least one described second position set, the interest point set, the first position set and it is described plus Close instruction information generates target query result.

Optionally, the set of at least one second position according to, the interest point set, the first position described Set and the encryption indication information, after generating target query result, further includes:

The target query is sent to the first terminal as a result, so that the first terminal is from the target query result In parse destination address and the destination address be sent to the second terminal.

Optionally, the set of at least one second position according to, the interest point set, the first position collection It closes and the encryption indication information, generation target query result, comprising:

According to corresponding position grouping, Yi Jisuo in first position set and at least one described second position set Interest point set is stated, determines candidate query as a result, the candidate target result includes multiple candidate sites；

According to the encryption indication information and the candidate query as a result, determining target query result.

Optionally, corresponding position grouping in being gathered described according to first position set and the second position, And the interest point set, before determining candidate query result, further includes:

According to the quantity of the second terminal, from first position set and at least one described second position set with Machine chooses at least two location sets；

It is described according to corresponding position grouping in first position set and second position set and described emerging Interesting point set determines candidate query result, comprising:

Corresponding position grouping and the interest point set at least two location sets according to randomly selecting It closes, determines candidate query result.

According to the quantity of the second terminal, the point of interest in the interest point set is randomly selected, generates choosing Interest point set after taking；

After corresponding position grouping in first position set and second position set and the selection Interest point set, determine candidate query result.

The fourth aspect of the present invention provides a kind of first terminal, comprising:

First sending module, for position arrangement information to be sent to second terminal, so that the second terminal is according to institute Rheme set arrangement information by the actual position of the second terminal and with the associated false position of the actual position of the second terminal It is combined into second position set；

First generation module, for according to the position arrangement information by the actual position of first terminal and with described first The associated false position grouping of the actual position of terminal is gathered at first position；

Second generation module, for generating encryption indication information, the encryption instruction letter according to the position arrangement information Breath is for cryptographically indicating position in the set of the first position of the actual position of the first terminal and described Position of the actual position of second terminal in the second position is gathered；

Third generation module, the instruction information for being inputted according to user generate interest point set；

Second sending module, for sending first position set, the encryption indication information and described to server Interest point set, so that the server is according to the interest point set, first position set, the encryption indication information Second position set with receiving from the second terminal, generates target query result.

Optionally, further includes:

4th receiving module, for receiving the target query result of server transmission；

Deciphering module obtains destination address for the target query result to be decrypted；

4th sending module, for the destination address to be sent to the second terminal.

First generation module, comprising:

First false position generates unit, for detecting the actual position of the first terminal and according to the first terminal Actual position and position generate the false position that private key generates multiple first terminals, and the position generation private key is used for will be true Position and false position are associated；

First reference set generation unit, for the genesis sequence according to the false position of the first terminal, by described The actual position of one terminal and first terminal vacation position are sequentially placed into the first reference set；

First position converter unit, for being converted to first reference set according to the position permutation matrix, Generate the first position set.

The fifth aspect of the present invention provides a kind of second terminal, comprising:

First receiving module, for receiving the position arrangement information of first terminal transmission；

4th generation module, according to the position arrangement information by the actual position of second terminal and with the second terminal The associated false position grouping of actual position gather at the second position；

Third sending module is gathered for sending the second position to server, so that the server is according to from the Interest point set, first position set, encryption indication information and the second position set that one terminal receives generate target Query result, the interest point set are described according to user's instruction generation, and the first position set is according to institute's rheme Set arrangement information by the actual position of the first terminal and with the associated false position grouping of the actual position of the first terminal At, the encryption indication information is generated according to the position arrangement information, and the encryption indication information refers to for encrypting Show the actual position of position and second terminal of the actual position of the first terminal in the set of the first position in institute State the position in the set of the second position.

Optionally, further include

5th receiving module, the destination address sent for receiving the first terminal, the destination address is by described First terminal receives the target query result that server is sent and generation is decrypted to the target query result.

4th generation unit, comprising:

Second false position generates unit, for detecting the actual position of the second terminal and according to the second terminal Actual position and position generate the false position that private key generates multiple second terminals, and the position generation private key is used for will be true Position and false position are associated；

Second reference set generation unit, for the genesis sequence according to the false position of the second terminal, by described The actual position of two terminals and second terminal vacation position are sequentially placed into the second reference set；

Second position converter unit, for being converted to second reference set according to the position permutation matrix, Generate the second position set.

The sixth aspect of the present invention provides a kind of server, comprising:

Second receiving module, for receiving the interest point set, first position set and encryption instruction of first terminal transmission Information, the interest point set are to indicate to generate according to user, and the first position set is to be arranged to believe according to the position Breath by the first terminal actual position and with the associated false position grouping of the actual position of the first terminal at, it is described Encryption indication information is generated according to the position arrangement information, and the encryption indication information is for encrypting instruction described first The actual position of position and second terminal of the actual position of terminal in the first position is gathered is in the second position Position in set；

Third receiving module obtains at least one for receiving the second position set of at least one second terminal transmission Second position set, second position set are by the actual position of the second terminal and true with the second terminal The associated false position grouping in position at；

Enquiry module, for according at least one described second position set, the interest point set, the first position Set and the encryption indication information generate target query result.

Optionally, further includes:

5th sending module, for sending the target query as a result, so that the first terminal to the first terminal Destination address is parsed from the target query result and the destination address is sent to the second terminal.

Optionally, the enquiry module, comprising:

With reference to query unit, for according to corresponding in first position set and at least one described second position set Position grouping and the interest point set, determine candidate query as a result, the candidate target result includes multiple candidate ground Location.

Final result unit is used for according to the encryption indication information and the candidate query as a result, determining target query As a result.

Optionally, the enquiry module, further includes:

First selection unit, for the quantity according to the second terminal, from first position set and it is described at least One second position set randomly selects at least two location sets；

It is described to refer to query unit, specifically for corresponding position at least two location sets according to randomly selecting Combination and the interest point set are set, determines candidate query result.

Optionally, the enquiry module, further includes:

Second selection unit clicks through the interest in the interest point set for the quantity according to the second terminal Row randomly selects, and generates the interest point set after choosing.

It is described to refer to query unit, it is specifically used for according to corresponding in first position set and second position set Position grouping and the selection after interest point set, determine candidate query result.

The seventh aspect of the present invention provides a kind of storage medium, is stored thereon with computer program, and the program is processed The method that first aspect or second aspect or the third aspect are related to is realized when device executes.

A kind of group's K-NN search method, first terminal, second terminal and server provided by the invention, by will be true Real position be associated with false position, and by position arrangement information by true place in first set and second set and vacation position into Row corresponds to, so that the false position generated every time when a position is repeatedly inquired is all the same, and different location in inquiry every time Position of the false position in set mutually corresponds in set, and then improves group's K-NN search secret protection ability.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is this hair Bright some embodiments for those of ordinary skill in the art without any creative labor, can be with It obtains other drawings based on these drawings.

Fig. 1 is a kind of schematic diagram of the application scenarios of group's K-NN search method provided in an embodiment of the present invention；

Fig. 2 is a kind of signaling interaction diagram of group's K-NN search method provided in an embodiment of the present invention；

Fig. 3 is a kind of applied field of group's K-NN search method of specified interest point set provided in an embodiment of the present invention The schematic diagram of scape；

Fig. 4 is the signaling interaction diagram of another group K-NN search method provided in an embodiment of the present invention；

Fig. 5 is a kind of flow diagram of step S22 provided in an embodiment of the present invention；

Fig. 6 is a kind of flow diagram of step S28 provided in an embodiment of the present invention；

Fig. 7 is the flow diagram of another step S28 provided in an embodiment of the present invention；

Fig. 8 is a kind of structural schematic diagram of first terminal provided in an embodiment of the present invention；

Fig. 9 is a kind of structural schematic diagram of first generation module provided in an embodiment of the present invention；

Figure 10 is the structural schematic diagram of second terminal provided in an embodiment of the present invention；

Figure 11 is a kind of structural schematic diagram of 4th generation module provided in an embodiment of the present invention；

Figure 12 is a kind of structural schematic diagram of server provided in an embodiment of the present invention；

Figure 13 is a kind of structural schematic diagram of enquiry module provided in an embodiment of the present invention；

Figure 14 is the structural schematic diagram of another enquiry module provided in an embodiment of the present invention.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.

In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only It is only a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill Personnel's every other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.

Specification of the invention and the term " first " in above-mentioned attached drawing, " second " etc. are to be used to distinguish similar objects, Without being used to describe a particular order or precedence order.It should be understood that the data used in this way in the appropriate case can be mutual It changes, so that the embodiment of the present invention described herein can be real with the sequence other than those of illustrating or describing herein It applies.

It should be appreciated that in various embodiments of the present invention, the size of the serial number of each process is not meant to execute sequence It is successive, the execution of each process sequence should be determined by its function and internal logic, the implementation without coping with the embodiment of the present invention Journey constitutes any restriction.

It should be appreciated that in the present invention, " comprising " and " having " and their any deformation, it is intended that covering is not arranged His includes, for example, the process, method, system, product or equipment for containing a series of steps or units are not necessarily limited to clearly Those of list step or unit, but may include be not clearly listed or for these process, methods, product or equipment Intrinsic other step or units.

It should be appreciated that in the present invention, " B corresponding with A ", " A and B are corresponding " or " B and A are corresponding " indicate B It is associated with A, B can be determined according to A.Determine that B is not meant to determine B only according to A according to A, can also according to A and/or Other information determines B.

Depending on context, as used in this " if " can be construed to " ... when " or " when ... " or " in response to determination " or " in response to detection ".

Technical solution of the present invention is described in detail with specifically embodiment below.These specific implementations below Example can be combined with each other, and the same or similar concept or process may be repeated no more in some embodiments.

Fig. 1 is a kind of schematic diagram of the application scenarios of group's K-NN search method provided in an embodiment of the present invention.

Referring to FIG. 1, the quantity of second terminal 102 can be one or more in scene applicatory of the embodiment of the present invention A, first terminal 101 is interacted with all second terminals 102 and server 103 respectively, and all second terminals 102 are and server 103 interactions.Specifically, first terminal 101 and second terminal 102 send location sets to server 103, so that server selects It takes out optimal location and feeds back to terminal.

It can use network implementations communication between first terminal 101, second terminal 102 and server 103.

Wherein, terminal can be the electronic equipment of arbitrary disposition processor, memory, can be such as: mobile phone, plate electricity The equipment such as brain, computer.

Server can be the electronic equipment of arbitrary disposition processor and memory or the set of electronic equipment.

Fig. 2 is a kind of signaling interaction diagram of group's K-NN search method provided in an embodiment of the present invention.

It please refers to such as Fig. 2, group's K-NN search method provided by the invention, including step S11-S18, specific as follows:

S11: position arrangement information is sent to second terminal by first terminal.

Position arrangement information can be the information of calibration actual position arrangement position in location sets.

In practical applications, if there is u in group₁,u₂Two users, by u₁As coordinates user, terminal is whole as first End, by u₂As auxiliary user, terminal is as second terminal.In the query generation stage, coordinates user u_cIt is wide by first terminal A position arrangement information is broadcast to the second terminal of other users, so that the actual position of first terminal is in first position is gathered Position and second terminal position of the actual position in the set of the second position it is identical.Specifically, position arrangement information can be with For position permutation matrix.

S12: first terminal according to position arrangement information by the actual position of first terminal and with the true position of first terminal Associated false position grouping is set to gather at first position.

False position, can be terminal generated according to the actual position of user it is unrelated with the actual position of user false Location information.

First position set can be the set of the location information of the actual position comprising first terminal and false position.

In practical applications, first terminal generates d-1 false position according to the actual position of oneself.Wherein, d hides for position Name parameter.Then, by the false position of generation and actual position composition first position set.Such as: the actual position of first terminal For l_1,1, it is l according to the false position that actual position generates_1,2,l_1,3, by the actual position of first terminal and false position composition first Location sets

S13: first terminal generates encryption indication information according to position arrangement information.

Encryption indication information, for cryptographically indicating position of the actual position of first terminal in the set of first position Set and the actual position of second terminal the second position gather in position.

In practical applications, encryption indication information can for by position arrangement information transformation generate encryption indicate to Amount, the encryption indicate the index of vector underlying identity actual position.

S14: first terminal generates interest point set according to the instruction information that user inputs.

Interest point set can be understood to the set of the location information type of the pre- inquiry of user's selection.

In practical applications, it is from a specified point of interest that group user can preset query result by first terminal It chooses in set, rather than is chosen in the interest point data base of entire server.As shown in figure 3,3 user u₁,u₂,u₃Phase Hope the smallest point of interest party of 1 crowding distance of selection, clothes from " difficult to understand body park, national park, music hall " this 3 sight spots Business provider has finally returned that " body park difficult to understand " and its relevant information (such as business hours, ticket price etc.) to group user. Even if there are the smaller points of interest of other crowding distances in the database of server, such as " Wal-Mart ", but the point of interest is not Meet the requirement of group user.In addition, when first terminal does not specify any point of interest, service provider then default groups be from It is selected in all points of interest of database.

S15: first terminal sends first position set, encryption indication information and interest point set to server.

Specifically, first position set, encryption indication information and interest point set are sent to server, so that server root According to interest point set, first position set, encryption indication information and the second position set received from second terminal, mesh is generated Mark query result.

S16: second terminal according to position arrangement information by the actual position of second terminal and with the true position of second terminal Associated false position grouping is set to gather at the second position.

Specifically, the step is identical as the specific implementation of S12, for duplicate content, it is not repeated herein.

S17: second terminal sends the second position to server and gathers.

In practical applications, the second position set of generation is sent to server by second terminal, if the number of second terminal Amount is not one, then the second set of generation is sent to server by each second terminal, so that server generates target Query result.

S18: server is gathered according at least one second position set, interest point set, first position and encryption indicates Information generates target query result.

In practical applications, server receives at least one second position set, interest point set, first position set After encryption indication information, location information to be checked is determined from the database of server according to interest point set first.Then Set address information corresponding with every group of position in the set of the second position in first position is found most in location information to be checked Neighbour address, by the arest neighbors address of all acquisitions candidate query result the most.It is determined wherein finally by encryption indication information The corresponding arest neighbors address of true address simultaneously generates target query result.

A kind of group's K-NN search method provided by the invention, by the way that actual position is associated with false position, Yi Jitong It crosses position arrangement information to correspond to true place in first set and second set and false position, so that multiple a position The false position generated every time when inquiry is all the same, and position of the false position in set in different location set in inquiry every time It mutually corresponds to, and then improves group's K-NN search secret protection ability.

Fig. 4 is the signaling interaction diagram of another group K-NN search method provided in an embodiment of the present invention.

Referring to figure 4., group provided by the invention leads querying method recently, comprising:

S21: position arrangement information is sent to second terminal by first terminal.

S22: first terminal according to position arrangement information by the actual position of first terminal and with the true position of first terminal Associated false position grouping is set to gather at first position.

S23: first terminal generates encryption indication information according to position arrangement information.

S24: first terminal generates interest point set according to the instruction information that user inputs.

S25: first terminal sends first position set, encryption indication information and interest point set to server.

S26: second terminal according to position arrangement information by the actual position of second terminal and with the true position of second terminal Associated false position grouping is set to gather at the second position.

S27: second terminal sends the second position to server and gathers.

S28: server is gathered according at least one second position set, interest point set, first position and encryption indicates Information generates target query result.

Step S21 can refer to the technical term of step S28, technical effect, technical characteristic and optional embodiment Step S11 to S18 shown in Fig. 2 understands, for duplicate content, is not repeated herein.

S29: server sends target query result to first terminal.

S30: target query result is decrypted in first terminal, obtains destination address.

S31: destination address is sent to second terminal by first terminal.

In practical applications, after server generates target query result, target query result can be sent to by server First terminal.Server can not parse destination address according to target query result, and first terminal can be to target query result It is parsed, obtain final destination address and destination address is sent to second terminal.

Fig. 5 is a kind of flow diagram of step S22 provided in an embodiment of the present invention.

Referring to figure 5., step S22, comprising:

S221: detecting the actual position of first terminal and generates private key generation according to the actual position of first terminal and position The false position of multiple first terminals.

Wherein, position generates private key and is used to for actual position and false position being associated.

In practical applications, when user is when same actual position repeats to inquire, the d-1 vacation position also phase generated Together, i.e. the actual position of user and false location sets is bundled in together.Specifically, can be generated by hash function model False position.

Before generating false position, preset One-Way Encryption hash function model that all users both know about (such as SHA-256):

Output:=H (K_i||l_{I, *}, id)

The input of hash function model H is three parameters, and the 1st is user u_iPrivate key K_i, the 2nd is actual position l_{I, *}, the 3rd be false position id number, range is from 1 to d-1.The output of hash function is the big integer of 256 bits Output contains the precision of false position and false position, it usually needs identical as the precision of actual position.

By traversing the id number of false position, user u_iAvailable d-1 false position, each vacation position may be spread over In entire locational space.It is noted that if user u_iWish false position in a certain range near actual position, that The user can specify formation range.After server receives actual position and false position, it is true position which, which counter can not be pushed away, It sets, which is false position, because only that each user u_iPossess respective private key.By keyed Hash function, when user is same When one position repeats to inquire, obtained d-1 vacation position is also all identical, and therefore, service provider can not simply check counterweight Location sets when inquiry carry out intersecting location privacy of the attack to destroy user.

S222: according to the genesis sequence of the false position of first terminal, the actual position of first terminal and first terminal is false Position is sequentially placed into the first reference set.

S223: according to position permutation matrix, converting the first reference set, generates first position set.

In practical applications, although when false position hash function model can cut off repetition inquiry between user location set Connection, still, due to be group inquiry, if only concern actual position placement location, server it is possible to The actual position of group user is speculated by the candidate query of generation.

In conjunction with concrete condition as an example it is assumed that d=3, there are two user u in group₁, u₂, initiated to inquire Q twice₁With Q₂.User u₁Actual position be l_{1, *}, two false positions are l_1,1And l_1,2；User u₂Actual position be l_{2, *}, two false positions For l_2,1And l_2,2.In Q₁In inquiry, two users are appointed on the 1st index that actual position is placed in location sets, False position random alignment, then location sets may be respectivelyWithAt this point, clothes 3 candidate query { l can be generated in business provider_{1, *}, l_{2, *}, { l_1,1, l_2,1, { l_1,2, l_2,2}.In Q₂In inquiry, two use Family equally arranges to be placed on actual position on the 1st index, false position random alignment, then location sets may be respectivelyWithAt this point, 3 candidate query { l can be generated in service provider_{1, *}, l_{2, *}, { l_1,2, l_2,1, { l_1,1, l_2,2}.It include identical position, clothes in the location sets of each user in inquiring twice It is that the repetition that same group of user carries out is inquired that business provider, which can learn that this is inquired twice, still, the candidate inquired twice Only having 1 in query set is identical address (l_{1, *}, l_{2, *}, then server can determine { l substantially_{1, *}, l_{2, *}It is group True address, remaining is all that the actual position of each user of false address is also leaked.

Therefore, a kind of simple method is each user regardless of which inquiry participated in, and is all placed on its actual position solid On fixed index, and false position is placed in location sets in numerical order, for example actual position is placed on the 1st index On, the 1st false position is placed on the 2nd index, and so on.Although this method can solve the above problem, but simultaneously It is dangerous and practical, because the index of actual position should not be taken as system parameter.Although can choose the index between user Value, and is broadcast to the every other user in system, but service provider can create a bogus subscriber that (user can not Participate in any inquiry), to obtain the index value of actual position, without allowing other users to find.

To solve the problems, such as that above-mentioned candidate query intersection of sets pitches attack, the method that location sets arrange is proposed, it is assumed that each User u_iAfter generating d-1 false position using false position hash method, all set initial location sets to

Wherein l_{I, j}Indicate j-th of false position, and the rest may be inferred.For groupEach inquiry, coordinates user u_cAt random The permutation matrix B of d × d dimension is generated, and is broadcasted to all users in group.Then each user is according to permutation matrix To initial position setIt rearranges, the location sets after being arrangedUser sends the location sets of transformation To server.

The specific implementation of S26 is identical as step S221-S223, for duplicate content, is not repeated herein.

Fig. 6 is a kind of flow diagram of step S28 provided in an embodiment of the present invention.

Referring to FIG. 6, step S28, comprising:

S281: it according to the quantity of second terminal, is randomly selected from first position set and at least one second position set At least two location sets.

S282: according to corresponding position grouping and interest point set at least two location sets randomly selected, really Determine candidate query result.

S283: according to encryption indication information and candidate query as a result, determining target query result.

In practical applications, portion set can be randomly selected to be inquired.Because intersecting in attack in inequality, Collusion user knows exactly which that all users take part in inquiry, so after listing inequality, it can be by their true position Substitution inequality is set, is obtained only comprising using target user's actual position as the inequality of known variables.Group user random selection The location sets for participating in inquiry can be randomly selected in method, to be blurred the information, collusion user just knows that certain customers exist In candidate query, but which user does not know is, to prevent collusion user from obtaining accurate inequality according to query result To attack.

Specifically, it is assumed that from group in approximate candidate queryIn randomly selected user's ratio be set as α, and α ∈ [0, 1].Candidate query generate when, server randomly choose location sets, be equivalent to fromSelect a subsetWherein meetSimply to state, it is assumed that α n is integer, then for each user u_iIt is chosen toIn probability Are as follows:

When executing inquiry, server can then be arrived according to point of interestCrowding distance select K point of interest as Target query result.When the query result that user receives service provider's return (is set as) after,In Point of interest can be according to crowding distance sequence, is also possible to unordered, is assumed to be herein unordered.It is noticeable It is that collusion user still can basisMiddle point of interest and setMiddle point of interest does inequality relation analysis.

Assuming that u₁It is target user, u₂..., u_nCollusion speculates u₁Actual position.In the randomly selected feelings of group user Under condition, there are two types of may.The first is u₁Not by service provider select intoIn, then collusion user can not obtain at this time u₁Any inequality information of actual position, therefore speculate that the probability of correct inequality is 0.Second is u₁Selected into In, but in order to obtain correct inequality information, collusion user also needs successfully to guess out from remaining n-1 user selected Select intoOther α n-1 users, the probability are as follows:

Both comprehensive possibilities, collusion user can correctly deduce about user u₁The inequality relation of actual position Total probability are as follows:

If for example, n=10, α=0.5, then the probability that collusion user deduces correct inequality isThe protection intensity of this method is related to α, and when α is very big or very little, the probability of above formula is all relatively Greatly, and when α is moderate, above formula probability is smaller.

Next when using this method, collusion user speculates the minimum value of correct inequality probability for concrete analysis, it is assumed that User's number n be it is fixed, then objective function isα n-1=x, i.e. α=(x+ are set first with substitution method 1)/n, then objective function can be transformed to:

It is easy analysis, when denominator is bigger, the value of the formula is smaller, that is, works asWhen, that is, When it is minimum, and the minimum value of probability is

Therefore, when the second position, collection is combined into multiple, server is to the first position set and second position collection received Conjunction is randomly choosed, and is inquired according to the location sets chosen, and secret protection ability can be improved.

Fig. 7 is the flow diagram of another step S28 provided in an embodiment of the present invention.

Referring to FIG. 7, step S28, comprising:

S284: according to second terminal quantity, randomly selecting the point of interest in interest point set, generates after choosing Interest point set.

S282: according to the interest after corresponding position grouping, and selection in first position set and second position set Point set determines candidate query result.

In practical applications, collusion user can be effectively reduced in the method for generating candidate query in random selection location sets Deduce the probability of correct inequality, but there is also a problems simultaneously: the location sets generated when user's number very little compared with Few, the minimum value of probability generally also can be very big, may be unable to satisfy user Section IV class secret protection intensity t set in advance.Than Such as n=4, the minimum probability that this method can achieve isIt cannot achieve if t=0.01.

At this point it is possible to using interest point set random selection method, it is similar to the randomly selected thinking of group user, it is assumed that From interest point set in approximate candidate queryIn randomly selected point of interest ratio be set as β, and β ∈ [0,1].This method from The interest point set that user specifiesMiddle a part of point of interest of random selection (is set asAnd meet) make Database when to inquire.In other words, K point of interest fromMiddle inquiry obtains.Equally, for simplicity, it is assumed that It is integer, then gathersIn each point of interest p be chosen toIn probability be

When having constructedAfterwards, server will beUpper execution group's k nearest neighbor inquiry, obtains query resultRightCoding Point of interest therein upsets sequence at random before, i.e.,It isThe middle the smallest K interest point set of crowding distance, but wherein simultaneously There is no the ordinal relations on crowding distance.When terminal receives the query result of service provider's returnAfterwards, becauseInterior interest Point set be it is unordered, according to theorem 1, inequality is constructed on unordered query result, disaggregation region is that entire position is empty Between, so collusion user can not basisAny supposition is done to the actual position of target user.

Safety on the unordered query result of theorem 1: n user u is given₁..., u_nInquiring position set If the query result that group receivesMiddle point of interest be it is disorderly arranged, then any one The disaggregation of a target user is entire locational space.

Specifically proof procedure is, it is assumed that u₁It is target user, u₂..., u_nIt is collusion user.BecauseIn point of interest It is disorderly arranged, so collusion user is merely able to attempt each arrangement to speculate l_{1, *}.Assuming that П indicates the institute of (1 ..., K) There is the set of arrangement, then shares K in П！A element.For any one arrangement (i1 ..., iK) in П, user's energy is conspired Enough deduce l_{1, *}A disaggregation, be set as R (p_i1..., p_iK).Therefore, l_{1, *}Disaggregation are as follows:

S=∪_{(i1 ..., iK) ∈ П}R(p_i1..., p_iK)

Next prove that S is entire locational space S_W, i.e. l_{1, *}It can be S_WAny point.It is proved using reduction to absurdity, it is false If S ≠ S_W, that is, there is a point l '₁∈{S_W-S}.Note that if given l '₁, collusion user is according to their position l_{2, *}..., l_{N, *}, the crowding distance of group's point of interest into query result can be calculated, and be ranked up according to crowding distance, obtain one The arrangement (i1 ' ..., iK ') of point of interest.But because П is the set of all possible arrangements, (i1 ' ..., iK ') ∈ П is necessarily set up, i.e. l '₁∈ S, with hypothesis test.So S=S_W, l_{1, *}Disaggregation be entire locational space, i.e., collusion user without Method does any deduction according to actual position of the unordered query result to target user.

According to the definition of approximate query,The crowding distance of middle point of interest comparesThe crowding distance of middle point of interest Greatly, collusion user can use the two set and generate inequality.However, collusion user can not determine in addition toExcept there are also which A little points of interest are chosen toIn, therefore, collusion user, which can only do, to be speculated.It is worth noting that, in this case, collusion is used Family does not need to guess allIn point of interest, as long as because hitting itIn a point of interest, then can With construct the point of interest withInequality relation between middle K point of interest.This information is repeating Snapshot query situation enough Under do intersection attack.Therefore, hit itIn a point of interest and construct the probability of correct inequality are as follows:

Due to β D_pThe minimum value of-K >=0, institute's above formula is zero, i.e. β D_p=K, connotation are that service provider only randomly chooses K A point of interest conductBecauseIn only K point of interest, so service provider can directly upset at randomAs looking into Ask result.Obviously, the result availability under this situation is bad, but can satisfy in the case where repeating request for information, conspires user Speculate that the probability of user's actual position is lower.

A kind of group's K-NN search method, first terminal, second terminal and server provided by the invention, by will be true Real position be associated with false position, and by position arrangement information by true place in first set and second set and vacation position into Row corresponds to, so that the false position generated every time when a position is repeatedly inquired is all the same, and different location in inquiry every time Position of the false position in set mutually corresponds in set, not only inherits the secret protection characteristic of existing scheme, can be with Protect user relative to the query result privacy of service provider, service provider relative to user database information privacy and Privacy relative to collusion user.

Fig. 8 is a kind of structural schematic diagram of first terminal provided in an embodiment of the present invention.

Referring to FIG. 8, first terminal, comprising:

First sending module 41, for position arrangement information to be sent to second terminal, so that second terminal is according to position Arrangement information is by the actual position of second terminal and with the associated false position grouping of the actual position of second terminal at the second position Set；

First generation module 42, for according to position arrangement information by the actual position of first terminal and with first terminal The associated false position grouping of actual position is gathered at first position；

Second generation module 43, for generating encryption indication information according to position arrangement information, encryption indication information is used for Cryptographically indicate the actual position of position and second terminal of the actual position of first terminal in the set of first position Position in the set of the second position；

Third generation module 44, the instruction information for being inputted according to user generate interest point set；

Second sending module 45, for sending first position set, encryption indication information and interest point set to server, So that server is according to interest point set, first position set, encryption indication information and the second received from second terminal Set is set, target query result is generated.

Optionally, further includes:

4th receiving module 46, for receiving the target query result of server transmission；

Deciphering module 47 obtains destination address for target query result to be decrypted；

4th sending module 48, for destination address to be sent to second terminal.

Fig. 9 is a kind of structural schematic diagram of first generation module provided in an embodiment of the present invention.

Referring to FIG. 9, position arrangement information is position permutation matrix, the first generation module, comprising:

First false position generates unit 421, for detecting the actual position of first terminal and according to the true of first terminal Position and position generate the false position that private key generates multiple first terminals, and position generates private key and is used for actual position and false position It is associated；

First reference set generation unit 422, for the genesis sequence according to the false position of first terminal, by first terminal Actual position and first terminal vacation position be sequentially placed into the first reference set；

First position converter unit 423 is generated for being converted to the first reference set according to position permutation matrix First position set.

Figure 10 is a kind of structural schematic diagram of second terminal provided in an embodiment of the present invention.

Please refer to Figure 10, second terminal, comprising:

First receiving module 51, for receiving the position arrangement information of first terminal transmission；

4th generation module 52, according to position arrangement information by the actual position of second terminal and true with second terminal The associated false position grouping in position is gathered at the second position；

Third sending module 53 is gathered for sending the second position to server, so that server is according to from first terminal Interest point set, first position set, encryption indication information and the second position set received generates target query as a result, emerging Interesting point set is to indicate to generate according to user, and first position set is the true position according to position arrangement information by first terminal Set and with the associated false position grouping of the actual position of first terminal at, encryption indication information is raw according to position arrangement information At, encryption indication information is used to encrypt position of the actual position of instruction first terminal in the set of first position, Yi Ji Position of the actual position of two terminals in the second position is gathered.

Optionally, further includes:

5th receiving module 54, for receiving the destination address of first terminal transmission, destination address is connect by first terminal It receives the target query result that server is sent and generation is decrypted to target query result.

Figure 11 is a kind of structural schematic diagram of 4th generation module provided in an embodiment of the present invention.

Please refer to Figure 11, the 4th generation module, comprising:

Second false position generates unit 521, for detecting the actual position of second terminal and according to the true of second terminal Position and position generate the false position that private key generates multiple second terminals, and position generates private key and is used for actual position and false position It is associated；

Second reference set generation unit 522, for the genesis sequence according to the false position of second terminal, by second terminal Actual position and second terminal vacation position be sequentially placed into the second reference set；

Second position converter unit 523 is generated for being converted to the second reference set according to position permutation matrix Second position set.

Figure 12 is a kind of structural schematic diagram of server provided in an embodiment of the present invention.

Please refer to Figure 12, server, comprising:

Second receiving module 61, interest point set, first position set and encryption for receiving first terminal transmission refer to Show that information, interest point set are to indicate to generate according to user, first position set is whole by first according to position arrangement information The actual position at end and with the associated false position grouping of the actual position of first terminal at, encryption indication information is according to position What arrangement information generated, encryption indication information is used to encrypt position of the actual position of instruction first terminal in the set of first position Set and the actual position of second terminal the second position gather in position；

Third receiving module 62 obtains at least one for receiving the second position set of at least one second terminal transmission A second position set, second position set are associated by the actual position of second terminal and with the actual position of second terminal False position grouping at；

Enquiry module 63, for gathering and encrypting according at least one second position set, interest point set, first position It indicates information, generates target query result.

Optionally, further includes:

5th sending module 64, for sending target query to first terminal as a result, so that first terminal is from target query As a result destination address is parsed in and destination address is sent to second terminal.

Figure 13 is a kind of structural schematic diagram of enquiry module provided in an embodiment of the present invention.

Please refer to Figure 13, enquiry module, comprising:

First selection unit 633, for the quantity according to second terminal, from first position set and at least one second It sets set and randomly selects at least two location sets.

With reference to query unit 631, specifically for according to corresponding set of locations at least two location sets randomly selected Conjunction and interest point set, determine candidate query result.

Final result unit 632 is used for according to encryption indication information and candidate query as a result, determining target query result.

Please refer to Figure 14, enquiry module, comprising:

Second selection unit 634 carries out the point of interest in interest point set random for the quantity according to second terminal It chooses, generates the interest point set after choosing.

With reference to query unit 631, it is specifically used for according to corresponding set of locations in first position set and second position set It closes, and the interest point set after selection, determines candidate query result.

First terminal, second terminal and server provided by the invention, by the way that actual position is associated with false position, and True place in first set and second set and false position are corresponded to by position arrangement information, so that more a position The false position generated every time when secondary inquiry is all the same, and position of the false position in set in different location set in inquiry every time It sets and mutually corresponds to, and then improve group's K-NN search secret protection ability.

The present invention also provides a kind of storage mediums, are stored thereon with computer program, real when which is executed by processor Information acquisition method in the voice communication of existing Fig. 2-Fig. 6.

Wherein, storage medium can be computer storage medium, be also possible to communication media.Communication media include convenient for from Any medium of one place to another place transmission computer program.Computer storage medium can be general or specialized meter Any medium that calculation machine can access.For example, storage medium is coupled to processor, to enable a processor to from the readable storage Medium reads information, and information can be written to the storage medium.Certainly, storage medium is also possible to the component part of processor.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention., rather than its limitations；To the greatest extent Pipe present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: its according to So be possible to modify the technical solutions described in the foregoing embodiments, or to some or all of the technical features into Row equivalent replacement；And these are modified or replaceed, various embodiments of the present invention technology that it does not separate the essence of the corresponding technical solution The range of scheme.

Claims

1. a kind of group's K-NN search method characterized by comprising

Position arrangement information is sent to second terminal, so that the second terminal is according to the position arrangement information by described The actual position of two terminals and gather with the associated false position grouping of the actual position of the second terminal at the second position；

According to the position arrangement information by the actual position of first terminal and with the actual position of the first terminal it is associated False position grouping is gathered at first position；

Encryption indication information is generated according to the position arrangement information, the encryption indication information is for cryptographically indicating institute The actual position of position and the second terminal of the actual position of first terminal in the set of the first position is stated in institute State the position in the set of the second position；

The first position set, the encryption indication information and the interest point set are sent to server, so that the clothes Be engaged in device according to the interest point set, the first position set, the encryption indication information and from the second terminal receive The second position set arrived, generates target query result.

2. the method according to claim 1, wherein it is described to server send first position set, After the encryption indication information and the interest point set, further includes:

Receive the target query result that server is sent；

The target query result is decrypted, destination address is obtained；

The destination address is sent to the second terminal.

3. the method according to claim 1, wherein the position arrangement information is position permutation matrix；

It is described to be closed according to the position arrangement information by the actual position of first terminal and with the actual position of the first terminal The false position grouping of connection is gathered at first position, comprising:

It detects the actual position of the first terminal and private key is generated according to the actual position of the first terminal and position and generate The false position of multiple first terminals, the position generate private key and are used to for actual position and false position being associated；

According to the genesis sequence of the false position of the first terminal, by the actual position of the first terminal and the first terminal False position is sequentially placed into the first reference set；

4. a kind of group's K-NN search method characterized by comprising

Receive the position arrangement information that first terminal is sent；

According to the position arrangement information by the actual position of second terminal and with the actual position of the second terminal it is associated False position grouping is gathered at the second position；

It sends the second position to server to gather, so that the server is according to the interest point set received from first terminal It closes, first position set, encryption indication information and second position set generate target query as a result, the interest point set It is described according to user's instruction generation, the first position set is according to the position arrangement information by the first terminal Actual position and with the associated false position grouping of the actual position of the first terminal at, the encryption indication information is root It is generated according to the position arrangement information, the encryption indication information indicates that the actual position of the first terminal exists for encrypting Position of the actual position of position and second terminal in the first position set in the set of the second position.

5. a kind of group's K-NN search method characterized by comprising

Receiving interest point set, first position set and encryption indication information, the interest point set that first terminal is sent is Generation is indicated according to user, and the first position set is according to the position arrangement information by the true of the first terminal Position and with the associated false position grouping of the actual position of the first terminal at, the encryption indication information is according to What position arrangement information generated, the encryption indication information, which is used to encrypt, indicates the actual position of the first terminal described the Position of the actual position of position and second terminal in one location sets in the second position is gathered；

The second position set that at least one described second terminal is sent is received, at least one second position set is obtained, it is described Second position set be by the second terminal actual position and with the associated false position of the actual position of the second terminal It is combined into；

Referred to according at least one described second position set, the interest point set, first position set and the encryption Show information, generates target query result.

6. according to the method described in claim 5, it is characterized in that, described at least one second position according to set, institute Interest point set, first position set and the encryption indication information are stated, target query result is generated, comprising:

According to corresponding position grouping and described emerging in first position set and at least one described second position set Interesting point set determines candidate query as a result, the candidate target result includes multiple candidate sites；

7. according to the method described in claim 6, it is characterized in that, described according to first position set and described second Corresponding position grouping and the interest point set in location sets, before determining candidate query result, further includes:

According to the quantity of the second terminal, from first position set and the random choosing of at least one described second position set Take at least two location sets；

It is described to be gathered and corresponding position grouping and the point of interest in the set of the second position according to the first position Set, determines candidate query result, comprising:

Corresponding position grouping and the interest point set at least two location sets according to randomly selecting, really Determine candidate query result.

8. a kind of first terminal characterized by comprising

First sending module, for position arrangement information to be sent to second terminal, so that the second terminal is according to institute's rheme Set arrangement information by the actual position of the second terminal and with the associated false position grouping of the actual position of the second terminal Gather at the second position；

First generation module, for according to the position arrangement information by the actual position of first terminal and with the first terminal The associated false position grouping of actual position gather at first position；

Second generation module, for generating encryption indication information according to the position arrangement information, the encryption indication information is used In cryptographically indicating the position and described second of the actual position of the first terminal in the set of the first position Position of the actual position of terminal in the second position is gathered；

Second sending module, for sending the first position set, the encryption indication information and the interest to server Point set so that the server according to the interest point set, the first position set, the encryption indication information and from The second position set that the second terminal receives, generates target query result.

9. a kind of second terminal characterized by comprising

4th generation module, according to the position arrangement information by the actual position of second terminal and true with the second terminal The associated false position grouping in real position is gathered at the second position；

Third sending module is gathered for sending the second position to server, so that the server is according to whole from first It terminates the interest point set received, first position set, encryption indication information and second position set and generates target query As a result, the interest point set is described according to user's instruction generation, the first position set is arranged according to the position Column information by the first terminal actual position and with the associated false position grouping of the actual position of the first terminal at, The encryption indication information is generated according to the position arrangement information, and the encryption indication information is for encrypting described in instruction The actual position of position and second terminal of the actual position of first terminal in the first position is gathered is described second Position in location sets.

10. a kind of server characterized by comprising

Second receiving module, for receiving the interest point set, first position set and encryption indication information of first terminal transmission, The interest point set is to indicate to generate according to user, and the first position set is according to the position arrangement information by institute State first terminal actual position and with the associated false position grouping of the actual position of the first terminal at, the encryption refers to Show that information is generated according to the position arrangement information, the encryption indication information is used to encrypt the instruction first terminal Position of the actual position of position and second terminal of the actual position in the first position is gathered in the set of the second position It sets；

Query unit, for according to described at least one described second position set, the interest point set, the first position Set and the encryption indication information generate target query result.