Distributed Storage System Having Hierarchical Secret Sharing

1 . A method for execution by one or more modules of one or more computing devices of a storage network, the method comprises:

encoding a data file to generate a set of encoded data shares using a first threshold based secret sharing scheme in accordance with first secret sharing parameters;

selecting a set of storage units of the storage network for storing the set of encoded data shares;

sending the set of encoded data shares to the set of storage units;

receiving, by a storage unit of the set of storage units, a first encoded data share of the set of encoded data shares;

encoding, by the storage unit, the first encoded data share using a second threshold based secret sharing scheme to generate a set of encoded data sub-shares; and

storing, by the storage unit, the set of encoded data sub-shares in a set of memory devices of the storage unit, wherein a threshold number of encoded data sub-shares of the set of encoded data sub-shares is decodable to recover the first encoded data share.

2 . The method of claim 1 further comprises:

receiving, by the storage unit, a read request for the first encoded data share from a requesting device;

rebuilding, by the storage unit, the first encoded data share from at least the threshold number of encoded data sub-shares of the set of encoded data sub-shares to provide a rebuilt encoded data share; and

sending, by the storage unit, the rebuilt encoded data share to the requesting device.

3 . The method of claim 1 further comprises:

receiving, by another storage unit of the set of storage units, another encoded data share of the set of encoded data shares;

encoding, by the another storage unit, the another encoded data share using a third threshold based secret sharing scheme in accordance with third secret sharing parameters to produce another set of encoded data sub-shares; and

storing, by the another storage unit, the another set of encoded data sub-shares in a set of memory devices of the another storage unit, wherein a threshold number of encoded data sub-shares of the another set of encoded data sub-shares is decodable to recover the another encoded data share.

4 . The method of claim 3 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme utilize a different threshold based secret sharing function.

5 . The method of claim 3 , wherein the threshold number of encoded data sub-shares of the set of encoded data sub-shares differs from the threshold number of encoded data sub-shares of the another set of encoded data sub-shares.

6 . The method of claim 1 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme utilize different threshold based secret sharing functions.

7 . The method of claim 1 further comprises:

determining the first secret sharing parameters based on one or more of a number of storage units of the set of storage units, a sub-sharing capability of one or more storage units of the set of storage units, or a reliability level of one or more storage units of the set of storage units.

8 . The method of claim 1 further comprises:

determining the second threshold based secret sharing scheme based on one or more of a number of memory devices of the storage unit, a reliability level of memory devices of the storage unit, an available capacity level of the memory devices of memory devices of the storage unit, or random selection.

9 . The method of claim 1 , wherein the first threshold based secret sharing scheme is an all-or-nothing transform with Reed Solomon coding (AONT-RS) secret sharing scheme.

10 . The method of claim 1 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme include at least one of an all-or-nothing transform with Reed Solomon coding (AONT-RS) secret sharing function, a Shamir secret sharing function, a Blakley secret sharing function, or a Rabin information dispersal algorithm (IDA) secret sharing function.

11 . A storage network device comprises:

a first module that stores operational instructions that, when executed by a computing device of a storage network, causes the computing device to:

encode, using a first threshold based secret sharing scheme in accordance with first secret sharing parameters, a data file to produce a set of encoded data shares;

select a set of storage units of the storage network for storing the set of encoded data shares; and

send the set of encoded data shares to the set of storage units; and

a second module that stores operational instructions that, when executed by a storage unit of the set of storage units, causes the storage unit to:

receive a first encoded data share of the set of encoded data shares;

encode the first encoded data share using a second threshold based secret sharing scheme in accordance with second secret sharing parameters to produce a set of encoded data sub-shares; and

store the set of encoded data sub-shares in a set of memory devices of the storage unit, wherein a threshold number of encoded data sub-shares of the encoded data sub-shares is decodable to recover the first encoded data share.

12 . The storage network device of claim 11 further comprises:

a third module further stores operational instructions that, when executed by the storage unit, causes the storage unit to:

receive a read request for the first encoded data share from a requesting device;

rebuild the first encoded data share from at least the threshold number of encoded data sub-shares of the set of encoded data sub-shares to provide a rebuilt first encoded data share; and

send the rebuilt first encoded data share to the requesting device.

13 . The storage network device of claim 11 further comprises:

a third module further stores operational instructions that, when executed by another storage unit of the set of storage units, causes the another storage unit to:

receive another encoded data share of the set of encoded data shares;

encode the another encoded data share using a third threshold based secret sharing scheme in accordance with third secret sharing parameters to produce another set of encoded data sub-shares; and

store the another set of encoded data sub-shares in a set of memory devices of the another storage unit, wherein a threshold number of encoded data sub-shares of the set of encoded data sub-shares is decodable to recover the another encoded data share.

14 . The storage network device of claim 13 , wherein the threshold number of encoded data sub-shares of the set of encoded data sub-shares differs from the threshold number of encoded data sub-shares of the another set of encoded data sub-shares.

15 . The storage network device of claim 13 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme utilize different threshold based secret sharing functions.

16 . The storage network device of claim 11 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme utilize a same threshold based secret sharing function.

17 . The storage network device of claim 11 , where the first module further stores operational instructions that, when executed by the storage network device, cause the computing device to:

determine the first secret sharing parameters for some storage units of the set of storage units, based on at least one of: a sub-sharing capability of the some storage units, or a reliability level of the some storage units.

18 . The device of claim 11 , where the second module further stores operational instructions that, when executed by the storage unit, causes the storage unit to:

determine the second secret sharing parameters for some storage units of the set of storage units, based on at least one of: a reliability level of memory devices of the storage unit, an available capacity level of memory devices of the memory devices of the storage unit, or random selection.

19 . The storage device of claim 11 , wherein the first threshold based secret sharing scheme is an all-or-nothing transform with Reed Solomon coding (AONT-RS) secret sharing scheme.

20 . The storage network device of claim 11 , wherein the first threshold based secret sharing scheme and the second threshold based secret sharing scheme include at least one of an all-or-nothing transform with Reed Solomon coding (AONT-RS) secret sharing function, a Shamir secret sharing function, a Blakley secret sharing function, or a Rabin information dispersal algorithm (IDA) secret sharing function.