PROXIMITY DETERMINATION METHOD, PROXIMITY DETERMINATION DEVICE, AND PROXIMITY DETERMINATION SYSTEM

• US 20140136094A1
• Filed: 10/08/2013
• Published: 05/15/2014
• Est. Priority Date: 11/12/2012
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: YASUDA, Masaya, YAJIMA, Jun, SHIMOYAMA, Takeshi, KOGURE, Jun
• Granted Patent: US 9,098,107 B2
• Time in Patent Office: Days
• US Class Current: 701/300
• CPC Class Codes: G06F 7/00 Methods or arrangements for processing data by operating upon the order or content of the data handled logic circuits H03K19/00
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A proximity determination method includes: collecting a first concealed vector based on a linear combination of a row vector of a key matrix, first numerical information, and a first random number, the key matrix being generated by adding a random number vector as a last column to a matrix in which a threshold for determining a proximity range is a diagonal element; collecting a second concealed vector based on the linear combination, second numerical information, and a second random number; calculating a remainder vector, the remainder vector being a remainder obtained from a difference between the collected first concealed vector and the second concealed vector when the key matrix is used as a modulus; and determining whether the first numerical information and the second numerical information belong to the proximity range, based on the calculated remainder vector.

Claims

1. A proximity determination method that is executed by a computer, the proximity determination method comprising:

collecting a first concealed vector based on a linear combination of a row vector of a key matrix, first numerical information, and a first random number, the key matrix being generated by adding a random number vector as a last column to a matrix in which a threshold for determining a proximity range is a diagonal element;

collecting a second concealed vector based on the linear combination, second numerical information, and a second random number;

calculating a remainder vector, the remainder vector being a remainder obtained from a difference between the collected first concealed vector and the second concealed vector when the key matrix is used as a modulus; and

determining whether the first numerical information and the second numerical information belong to the proximity range, based on the calculated remainder vector.

2. The proximity determination method according to claim 1, further comprising:

collecting a third concealed vector based on another linear combination that is different from the linear combination, the second numerical information, and the second random number.

3. The proximity determination method according to claim 1,

wherein the first concealed vector has a value obtained by adding the first numerical information to a product of the linear combination and the first random number, and

wherein the second concealed vector has a value obtained by adding the second numerical information to a product of the linear combination and the second random number.

4. The proximity determination method according to claim 1,

wherein the first numerical information indicates a position of a first information processing device, and

wherein the second numerical information indicates a position of a second information processing device.

5. A proximity determination device comprising:

a memory; and

a processor coupled to the memory and configured to

collect a first concealed vector based on a linear combination of a row vector of a key matrix, first numerical information, and a first random number, the key matrix being generated by adding a random number vector as a last column to a matrix in which a threshold for determining a proximity range is a diagonal element;

collect a second concealed vector based on the linear combination, second numerical information, and a second random number;

calculate a remainder vector, the remainder vector being a remainder obtained from a difference between the collected first concealed vector and the second concealed vector when the key matrix is used as a modulus; and

determine whether the first numerical information and the second numerical information belong to the proximity range, based on the calculated remainder vector.

6. The proximity determination device according to claim 5, the processor further configured to collect a third concealed vector based on another linear combination that is different from the linear combination, the second numerical information, and the second random number.

7. The proximity determination device according to claim 5,

wherein the first concealed vector has a value obtained by adding the first numerical information to a product of the linear combination and the first random number, and

wherein the second concealed vector has a value obtained by adding the second numerical information to a product of the linear combination and the second random number.

8. The proximity determination device according to claim 5,

wherein the first numerical information indicates a position of a first information processing device, and

wherein the second numerical information indicates a position of a second information processing device.

9. A proximity determination system comprising:

a key matrix generation device including a first memory and a first processor, wherein the first processor is coupled to the first memory and configured to;

generate a key matrix, the key matrix being generated by adding a random number vector as a last column to a matrix in which a threshold for determining whether first numerical information stored in a first information processing device and second numerical information stored in a second information processing device belong to a proximity range is a diagonal element,

send a linear combination of a row vector of the key matrix to the first information processing device and the second information processing device, and

send the key matrix; and

p1 a proximity determination device including a second memory and a second processor, wherein the second processor is coupled to the second memory and configured to;

receive the key matrix from the key matrix generation device,

collect a first concealed vector from the first information processing device based on the linear combination, the first numerical information, and a first random number,

collect a second concealed vector from the second information processing device based on the linear combination, the second numerical information, and a second random number,

calculate a remainder vector, the remainder vector being a remainder obtained from a difference between the first concealed vector and the second concealed vector when the key matrix is used as a modulus, and

determine whether the first numerical information and the second numerical information belong to the proximity range, based on the remainder vector.

10. The proximity determination system according to claim 9, the second processor is further configured to collect a third concealed vector based on another linear combination that is different from the linear combination, the second numerical information, and the second random number.

11. The proximity determination system according to claim 9,

wherein the first concealed vector has a value obtained by adding the first numerical information to a product of the linear combination and the first random number, and

wherein the second concealed vector has a value obtained by adding the second numerical information to a product of the linear combination and the second random number.

12. The proximity determination system according to claim 9,

wherein the first numerical information indicates a position of the first information processing device, and

wherein the second numerical information indicates a position of the second information processing device.