Verifying encoded data slice integrity in a dispersed storage network

1. A method for execution by a processing module of a storage device, the method comprises:

receiving, from a requesting entity, an encoded data slice of a set of encoded data slices, wherein a data segment is encoded using a dispersed storage error coding function to produce the set of encoded data slices, in which only a threshold number of the set of encoded data slices are needed to reconstruct the data segment, the threshold number being less than all of the set of encoded data slices, wherein a respective encoded data slice of the set of encoded data slices has associated therewith a respective integrity value, in which integrity information is generated from integrity values corresponding to encoded data slices of the set of encoded data slices, and wherein the set of encoded data slices are separated into individual encoded data slices and distributed to a plurality of devices along with the integrity information;

generating, by the processing module, an integrity value for the encoded data slice received from the requesting entity;

obtaining, by the processing module, at least a portion of the integrity information from another storage device that did not provide the received encoded data slice;

generating, by the processing module, a comparative integrity value for the encoded data slice based on the at least a portion of the integrity information obtained from the other storage device; and

facilitating, by the processing module, storage of the encoded data slice in memory of the storage device when the integrity value is same as the comparative integrity value.

2. The method of claim 1 further comprises:

receiving the encoded data slice as part of a rebuilding process, wherein the encoded data slice is a rebuilt encoded data slice corresponding to one of a corrupt encoded data slice of the set of encoded data slices.

3. The method of claim 1 further comprises:

obtaining, via a request, a retrieved integrity value of the encoded data slice from the other storage device, wherein the other storage device produced the retrieved integrity value from the integrity information; and

generating the comparative integrity value by equating the comparative integrity value to the retrieved integrity value.

4. The method of claim 1 further comprises:

obtaining, via a request, the integrity information from the other storage device;

producing a retrieved integrity value from the integrity information; and

generating the comparative integrity value by equating the comparative integrity value to the retrieved integrity value.

5. The method of claim 1 further comprises:

obtaining, by the processing module, a second at least a portion of the integrity information from a second other storage device; and

generating, by the processing module, the comparative integrity value for the encoded data slice based on the at least a portion of the integrity information and the second at least a portion of the integrity information.

6. The method of claim 1 further comprises:

generating an error message when the integrity value is not the same as the comparative integrity value.

7. A method for execution by a processing module of a storage device, the method comprises:

receiving, from a requesting entity, integrity information and an encoded data slice of a set of encoded data slices, wherein a data segment is encoded using a dispersed storage error coding function to produce the set of encoded data slices, in which only a threshold number of the set of encoded data slices are needed to reconstruct the data segment, the threshold number being less than all of the set of encoded data slices, wherein a respective encoded data slice of the set of encoded data slices has associated therewith a respective integrity value, in which the integrity information is generated from integrity values corresponding to encoded data slices of the set of encoded data slices, and wherein the set of encoded data slices are separated into individual encoded data slices and distributed to a plurality of devices along with the integrity information;

obtaining, by the processing module, at least a portion of a copy of the integrity information from another storage device that did not provide the received encoded data slice;

comparing, by the processing module, the at least a portion of the copy of the integrity information with a corresponding at least a portion of the received integrity information to determine if the integrity value from two different locations for the received encoded data slice are same; and

facilitating, by the processing module, storage of the encoded data slice in memory of the storage device when the comparison is the same.

8. The method of claim 7 further comprises:

generating, by the processing module, an integrity value for the encoded data slice;

obtaining, via a request, a retrieved integrity value of the encoded data slice from the other storage device, wherein the other storage device produced the retrieved integrity value from the copy of the integrity information; and

comparing the integrity value as the corresponding at least a portion of the received integrity information with the retrieved integrity value as the at least a portion of the copy of the integrity information.

9. The method of claim 7 further comprises:

obtaining, by the processing module, the copy of the integrity information from the other storage device; and

comparing, by the processing module, the copy of the integrity information with the received integrity information.

10. The method of claim 7 further comprises:

receiving the encoded data slice as part of a rebuilding process, wherein the encoded data slice is a rebuilt encoded data slice corresponding to one of a corrupt encoded data slice of the set of encoded data slices.

11. A dispersed storage (DS) module of a storage device, the DS module comprises:

a first module, when operable within a computing device, causes the computing device to:

receive, from a requesting entity, an encoded data slice of a set of encoded data slices, wherein a data segment is encoded using a dispersed storage error coding function to produce the set of encoded data slices, in which only a threshold number of the set of encoded data slices are needed to reconstruct the data segment, the threshold number being less than all of the set of encoded data slices, wherein a respective encoded data slice of the set of encoded data slices has associated therewith a respective integrity value, in which integrity information is generated from integrity values corresponding to encoded data slices of the set of encoded data slices, and wherein the set of encoded data slices are separated into individual encoded data slices and distributed to a plurality of devices along with the integrity information; and

generate an integrity value for the encoded data slice received from the requesting entity;

a second module, when operable within the computing device, causes the computing device to:

obtain at least a portion of the integrity information from another storage device that did not provide the received encoded data slice; and

generate a comparative integrity value for the encoded data slice based on the at least a portion of the integrity information obtained from the other storage device; and

a third module, when operable within the computing device, causes the computing device to:

facilitate storage of the encoded data slice in memory of the storage device when the integrity value is same as the comparative integrity value.

12. The DS module of claim 11 further comprises:

the first module further functions to receive the encoded data slice as part of a rebuilding process, wherein the encoded data slice is a rebuilt encoded data slice corresponding to one of a corrupt encoded data slice of the set of encoded data slices.

13. The DS module of claim 11 further comprises:

the second module further functions to:

obtain, via a request, a retrieved integrity value of the encoded data slice from the other storage device, wherein the other storage device produced the retrieved integrity value from the integrity information; and

generate the comparative integrity value by equating the comparative integrity value to the retrieved integrity value.

14. The DS module of claim 11 further comprises:

the second module further functions to:

obtain, via a request, the integrity information from the other storage device;

produce a retrieved integrity value from the integrity information; and

generate the comparative integrity value by equating the comparative integrity value to the retrieved integrity value.

15. The DS module of claim 11 further comprises:

the second module further functions to:

obtain a second at least a portion of the integrity information from a second other storage device; and

generate the comparative integrity value for the encoded data slice based on the at least a portion of the integrity information and the second at least a portion of the integrity information.

16. The DS module of claim 11 further comprises:

the third module further functions to generate an error message when the integrity value is not the same as the comparative integrity value.

17. A dispersed storage (DS) module of a storage device, the DS module comprises:

a first module, when operable within a computing device, causes the computing device to:

receive, from a requesting entity, integrity information and an encoded data slice of a set of encoded data slices, wherein a data segment is encoded using a dispersed storage error coding function to produce the set of encoded data slices, in which only a threshold number of the set of encoded data slices are needed to reconstruct the data segment, the threshold number being less than all of the set of encoded data slices, wherein a respective encoded data slice of the set of encoded data slices has associated therewith a respective integrity value, in which the integrity information is generated from integrity values corresponding to encoded data slices of the set of encoded data slices, and wherein the set of encoded data slices are separated into individual encoded data slices and distributed to a plurality of devices along with the integrity information;

a second module, when operable within the computing device, causes the computing device to:

obtain at least a portion of a copy of the integrity information from another storage device that did not provide the received encoded data slice; and

a third module, when operable within the computing device, causes the computing device to:

compare the at least a portion of the copy of the integrity information with a corresponding at least a portion of the received integrity information to determine if the integrity value from two different locations for the received encoded data slice are same; and

facilitate storage of the encoded data slice in memory of the storage device when the comparison is the same.

18. The DS module of claim 17 further comprises:

the first module further functions to generate an integrity value for the encoded data slice;

the second module further functions to obtain, via a request, a retrieved integrity value of the encoded data slice from the other storage device, wherein the other storage device produced the retrieved integrity value from the copy of the integrity information; and

the third module further functions to compare the integrity value as the corresponding at least a portion of the received integrity information with the retrieved integrity value as the at least a portion of the copy of the integrity information.

19. The DS module of claim 17 further comprises:

the second module further functions to obtain the copy of the integrity information from the other storage device; and

the third module further functions to compare the copy of the integrity information with the received integrity information.

20. The DS module of claim 17 further comprises:

the first module further functions to receive the encoded data slice as part of a rebuilding process, wherein the encoded data slice is a rebuilt encoded data slice corresponding to one of a corrupt encoded data slice of the set of encoded data slices.