Information processing system, information processing apparatus, method for information processing, and non-transitory computer-readable recording medium having stored therein information processing program

• US 10,574,455 B2
• Filed: 04/16/2018
• Issued: 02/25/2020
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: Tohoku University National Universities Corporation
• Original Assignee: Tohoku University National Universities Corporation
• Inventors: Hasegawa, Shingo, Iwazaki, Junya, Sakai, Masao, Takahashi, Daiki, Fukumitsu, Masayuki
• Primary Examiner(s): Rahim, Monjur
• Application Number:
  US15/954,011
• Publication Number:
  US 20180234239A1
• Time in Patent Office: 680 Days
• Field of Search: 726 6
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• CPC Class Codes: G06F 21/45 Structures or tools for the administration of authentication
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G09C 1/00 Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system cryptographic typewriters G09C3/00
• CPC Class Codes: H04L 9/085 Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

An information processing system including multiple memory devices and a processor configured to select one node group associated with a time point included in a time period between a current time point and a time point before a predetermined time including the current time point among multiple node groups each associated with one of multiple time points, and store the N pieces of distributed data one to each of N memory devices included in the selected node group. The information processing system carries out a restoring process on at least one of the multiple node groups, and if the restoring results in failure, carries out the restoring process on a second node group associated with a time point before a time point associated with the first node group that causes the failure among the plurality of node groups.

Claims

1. An information processing system comprising:

M (M represents an integer of two or more) memory devices;

a processor configured to;

generate N (N represents an integer of two or more and M or less) pieces of distributed data from secret data in accordance with a secret sharing scheme;

select one node group associated with a time point included in a time period between a current time point and a time point before a predetermined time from the current time point among a plurality of node groups each being associated with one of a plurality of time points and each including C (C is an integer of N or more and M or less) memory devices selected from the M memory devices, and store the N pieces of distributed data one to each of N memory devices included in the selected node group; and

carry out a restoring process on a first node group among the plurality of node groups,

the restoring process comprising;

requesting at least one of N memory devices included in the first node group for the distributed data;

restoring the secret data from a provided data provided in response to the requesting in accordance with the secret sharing scheme; and

if the restoring results in failure, carrying out the restoring process on a second node group associated with a time point before a time point associated with the first node group that causes the failure among the plurality of node groups.

2. The information processing system according to claim 1, wherein the processor is further configured to:

receive a storing request in association with input information input from a user, and if the storing request is received, sets the plurality of node groups on the basis of the input information associated with the storing request; and

receive a restoring request in association with input information input from a user, and if the restoring request is received, sets the plurality of node groups on the basis of the input information associated with the restoring request.

3. The information processing system according to claim 1, wherein:

the plurality of node groups are set on the basis of a plurality of pieces of device rank information each associated with one of the plurality of time points and a predetermined information rank relationship between the input information and C different ranks, and

the device rank information represents at least one of the M memory devices and a rank provided to the at least one memory device.

4. The information processing system according to claim 1, wherein:

the plurality of node groups are set on the basis of device rank information representing at least one of the M memory devices and a rank provided to the at least one memory device and information rank relationships each associated with one of the plurality of time points; and

the information rank relationship is a predetermined relationship between the input information and C different ranks.

5. The information processing system according to claim 1, wherein the secret data includes information representing a plurality of memory devices each storing one of a plurality of pieces of distributed data generated from secret data different from the secret data in accordance with the secret sharing scheme.

6. The information processing system according to claim 1, wherein the processor further configured to receive time period information representing a time period and being input from a user, and limit a group node that is to undergo the restoring process to one or more node groups associated with time points within the time period represented by the time period information among the plurality of node groups.

7. The information processing system according to claim 1, wherein the processor further configured to generate identification information on the basis of the time point associated with the selected node group, and store each of the N pieces of distributed data in association with the generated identification information.

8. The information processing system according to claim 7, wherein the processor further configured to generate, as the identification information, information different with each of N memory devices included in the selected node group.

9. The information processing system according to claim 1, wherein:

the number C of memory devices included in the node group is set to be larger as a password used for authenticating a user is more easily specified;

the processor further configured to randomly select N memory devices from among the C memory devices included in the selected node group and stores the N generated pieces of distributed data each into one of the N selected memory devices; and

the restoring process comprises requesting C memory devices included in the first node group for the distributed data, and restoring the secret data from each of one or more combinations of N pieces of provided data selected from C pieces of provided data provided in response to the requesting in accordance with the secret sharing scheme.

10. The information processing system according to claim 1, wherein:

the requesting for the distributed data to the memory device is made by an information processing apparatus transmitting a providing request including time point specification information that specifies a time point and one of input information input from the user or generated information generated based on the input information to the memory device; and

the processor further configured to

prohibit, if the information processing apparatus transmits a predetermined number or more of the providing requests common in the time point specification information and different in the input information or the generating information within a predetermined determination time period, providing of the providing data in response to the request from the information processing apparatus.

11. An information processing apparatus communicably connected to M (M represents an integer of two or more) memory devices, the information processing apparatus comprising a processor configured to:

generate N (N represents an integer of two or more and M or less) pieces of distributed data from secret data in accordance with a secret sharing scheme;

select one node group associated with a time point included in a time period between a current time point and a time point before a predetermined time from the current time point among a plurality of node groups each being associated with one of a plurality of time points and each including C (C is an integer of N or more and M or less) memory devices selected from the M memory devices, and store the N pieces of distributed data one to each of N memory devices included in the selected node group; and

carry out a restoring process on a first node group among the plurality of node groups,

the restoring process comprising;

requesting at least one of N memory devices included in the first node group for the distributed data;

restoring the secret data from a provided data provided in response to the requesting in accordance with the secret sharing scheme; and

if the restoring results in failure, carrying out the restoring process on a second node group associated with a time point before a time point associated with the first node group that causes the failure among the plurality of node groups.

12. A method for information processing using M (M represents an integer of two or more) memory devices, the method comprising:

generating N (N represents an integer of two or more and M or less) pieces of distributed data from secret data in accordance with a secret sharing scheme;

selecting one node group associated with a time point included in a time period between a current time point and a time point before a predetermined time from the current time point among a plurality of node groups each being associated with one of a plurality of time points and each including C (C is an integer of N or more and M or less) memory devices selected from the M memory devices, and storing the N pieces of distributed data one to each of N memory devices included in the selected node group; and

carrying out a restoring process on a first node group among the plurality of node groups,

the restoring process comprising;

requesting at least one of N memory devices included in the first node group for the distributed data;

restoring the secret data from a provided data provided in response to the requesting in accordance with the secret sharing scheme; and

if the restoring results in failure, carrying out the restoring process on a second node group associated with a time point before a time point associated with the first node group that causes the failure among the plurality of node groups.

13. A non-transitory computer-readable recording medium having stored therein an information processing program that causes an information processing apparatus communicably connected to M (M represents an integer of two or more) memory devices to execute a process comprising:

generating N (N represents an integer of two or more and M or less) pieces of distributed data from secret data in accordance with a secret sharing scheme;

selecting one node group associated with a time point included in a time period between a current time point and a time point before a predetermined time from the current time point among a plurality of node groups each being associated with one of a plurality of time points and each including C (C is an integer of N or more and M or less) memory devices selected from the M memory devices, and storing the N pieces of distributed data one to each of N memory devices included in the selected node group; and

carrying out a restoring process on a first node group among the plurality of node groups,

the restoring process comprising;

requesting at least one of N memory devices included in the first node group for the distributed data;

restoring the secret data provided in response to the requesting in accordance with the secret sharing scheme; and

if the restoring results in failure, carrying out the restoring process on a second node group associated with a time point before a time point associated with the first node group that causes the failure among the plurality of node groups.