Securely recovering stored data in a dispersed storage network

• US 10,372,357 B2
• Filed: 08/14/2018
• Issued: 08/06/2019
• Est. Priority Date: 08/31/2015
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Resch, Jason K.
• Primary Examiner(s): Chai, Longbit
• Application Number:
  US16/102,940
• Publication Number:
  US 20180356999A1
• Time in Patent Office: 357 Days
• Field of Search: 713193
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/3034 where the computing system component is a storage system, e.g. DASD based or network based digital input from or digital output to record carriers G06F3/06; digital recording or reproducing G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/3409 for performance assessment
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 2212/1052 Security improvement
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0622 in relation to access
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• CPC Class Codes: H04L 67/1097 : for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A method for execution by a dispersed storage and task (DST) execution unit that includes a processor includes receiving a slice pre-image request from a computing device via a network that indicates a data slice, a requesting entity and a plurality of storage units. A data pre-image is generated by performing a pre-image function on the data slice based on the plurality of storage units. An encrypted data pre-image is generated for transmission to the computing device by performing an encryption function on the data pre-image based on a key associated with the requesting entity.

Claims

1. A method for execution by a dispersed storage and task (DST) execution unit that includes a hardware processor, the method comprises:

generating, based on a slice pre-image request from a computing device, a data pre-image by performing a pre-image function on a data slice based on a plurality of storage units indicated in the request; and

generating an encrypted data pre-image for transmission to the computing device by performing an encryption function on the data pre-image based on a key associated with a requesting entity;

wherein the computing device receives a plurality of encrypted data pre-images from a plurality of storage units that includes the DST execution unit for transmission to the requesting entity for decoding;

wherein the requesting entity receives a plurality of storage unit identifiers corresponding to the plurality of storage units from the computing device, and wherein the requesting entity decodes the plurality of encrypted data pre-images by utilizing a plurality of unique keys, each associated with one of the plurality of storage units; and

wherein the requesting entity receives a sum of the encrypted data pre-images from the computing device, and wherein decoding includes subtracting each of the plurality of unique keys from the sum of the encrypted data pre-images.

2. The method of claim 1, wherein the slice pre-image request indicates the data slice, the requesting entity, and the plurality of storage units.

3. The method of claim 1, wherein the pre-image function includes creating a vector that includes the data slice.

4. The method of claim 3, wherein the pre-image function further includes creating a decode matrix based on the plurality of storage units.

5. The method of claim 4, wherein the pre-image function further includes performing matrix multiplication on the vector and the decode matrix.

6. The method of claim 1, wherein generating the encryption function includes applying the key additively to the data pre-image.

7. The method of claim 1, further comprising generating a message authentication code based on the data slice for transmission to the computing device.

8. The method of claim 1, wherein the key is established based on at least one of:

a public-key system or a key agreement protocol.

9. A processing system of a dispersed storage and task (DST) execution unit comprises:

at least one hardware processor;

a memory that stores operational instructions, that when executed by the at least one hardware processor cause the processing system to perform operations including;

generating, based on a slice pre-image request from a computing device, a data pre-image by performing a pre-image function on a data slice based on a plurality of storage units indicated in the request; and

generating an encrypted data pre-image for transmission to the computing device by performing an encryption function on the data pre-image based on a key associated with a requesting entity;

wherein the computing device receives a plurality of encrypted data pre-images from a plurality of storage units that includes the DST execution unit for transmission to the requesting entity for decoding;

wherein the requesting entity receives a plurality of storage unit identifiers corresponding to the plurality of storage units from the computing device, and wherein the requesting entity decodes the plurality of encrypted data pre-images by utilizing a plurality of unique keys, each associated with one of the plurality of storage units; and

wherein the requesting entity receives a sum of the encrypted data pre-images from the computing device, and wherein decoding includes subtracting each of the plurality of unique keys from the sum of the encrypted data pre-images.

10. The processing system of claim 9, wherein the pre-image function includes creating a vector that includes the data slice, creating a decode matrix based on the plurality of storage units, and performing matrix multiplication on the vector and the decode matrix.

11. The processing system of claim 9, wherein generating the encryption function includes applying the key additively to the data pre-image.

12. The processing system of claim 9, wherein the operations further include:

generating a message authentication code based on the data slice for transmission to the computing device.

13. The processing system of claim 9, wherein the key is established based on at least one of:

a public-key system or a key agreement protocol.

14. The processing system of claim 9, wherein the slice pre-image request indicates the data slice, the requesting entity, and the plurality of storage units.

15. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage and task (DST) execution unit that includes a hardware processor and a memory, causes the processing system to perform operations including;

generating, based on a slice pre-image request from a computing device, a data pre-image by performing a pre-image function on a data slice based on a plurality of storage units indicated in the request; and

generating an encrypted data pre-image for transmission to the computing device by performing an encryption function on the data pre-image based on a Key associated with a requesting entity;

wherein the computing device receives a plurality of encrypted data pre-images from a plurality of storage units that includes the DST execution unit for transmission to the requesting entity for decoding;

wherein the requesting entity receives a plurality of storage unit identifiers corresponding to the plurality of storage units from the computing device, and wherein the requesting entity decodes the plurality of encrypted data pre-images by utilizing a plurality of unique keys, each associated with one of the plurality of storage units; and

wherein the requesting entity receives a sum of the encrypted data pre-images from the computing device, and wherein decoding includes subtracting each of the plurality of unique keys from the sum of the encrypted data pre-images.

16. The computer readable storage medium of claim 15, wherein the pre-image function includes creating a vector that includes the data slice.

17. The computer readable storage medium of claim 16, wherein the pre-image function further includes creating a decode matrix based on the plurality of storage units, and performing matrix multiplication on the vector and the decode matrix.

18. The computer readable storage medium of claim 15, wherein generating the encryption function includes applying the key additively to the data pre-image.

19. The computer readable storage medium of claim 15, wherein the operations further include generating a message authentication code based on the data slice for transmission to the computing device.

20. The computer readable storage medium of claim 15, wherein the slice pre-image request indicates the data slice, the requesting entity, and the plurality of storage units.