STORAGE OF SENSITIVE DATA IN A DISPERSED STORAGE NETWORK

• US 20110286594A1
• Filed: 04/29/2011
• Published: 11/24/2011
• Est. Priority Date: 05/19/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Dhuse, Greg, Resch, Jason K., Leggette, Wesley, Baptist, Andrew
• Granted Patent: US 8,861,727 B2
• Time in Patent Office: Days
• US Class Current: 380/46
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• 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]
• CPC Class Codes: H04L 9/085 Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/0863 involving passwords or one-time passwords network architectures or network communication protocols for using one-time keys in a packet data network H04L63/067
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms

Abstract

A method begins by a processing module applying a share encoding function on data to produce a plurality of encoded shares and generating a corresponding plurality of random numbers for the plurality of encoded shares. The method continues with the processing module generating an encryption key based on a common password and a corresponding one of the corresponding plurality of random numbers and encrypting the encoded share utilizing the encryption key to produce an encrypted share for each encoded share of the plurality of encoded shares. The method continues with the processing module facilitating storage of the corresponding plurality of random numbers and each of the encrypted shares.

Claims

1. A method comprises:

applying a share encoding function on data to produce a plurality of encoded shares;

generating a corresponding plurality of random numbers for the plurality of encoded shares;

for each encoded share of the plurality of encoded shares;

generating an encryption key based on a common password and a corresponding one of the corresponding plurality of random numbers; and

encrypting the encoded share utilizing the encryption key to produce an encrypted share; and

facilitating storage of the corresponding plurality of random numbers and each of the encrypted shares.

2. The method claim 1, wherein the share encoding function comprises at least one of:

a dispersed storage error encoding function; and

a secret sharing function.

3. The method of claim 1, wherein the generating the corresponding plurality of random numbers comprises:

obtaining a plurality of base random numbers; and

expanding each base random number of the plurality of base random numbers based on security parameters to produce the corresponding plurality of random numbers.

4. The method of claim 1, wherein the generating the encryption key comprises:

transforming the common password utilizing a mask generating function, security parameters, and the corresponding one of the corresponding plurality of random numbers.

5. The method of claim 1, wherein the facilitating storage of the corresponding plurality of random numbers and the encrypted shares comprises at least one of:

sending the encrypted share and the corresponding one of the corresponding plurality of random numbers to a dispersed storage (DS) processing unit;

dispersed storage error encoding the encrypted share to produce a plurality of encoded share slices and outputting the plurality of encoded share slices for storage; and

dispersed storage error encoding the corresponding one of the corresponding plurality of random numbers to produce a plurality of encoded random number slices and outputting the plurality of encoded random number slices for storage.

6. A method comprises:

retrieving at least a decode threshold number of stored random numbers to produce a set of stored random numbers;

retrieving at least a decode threshold number of encrypted shares to produce a set of encrypted shares, wherein the set of encrypted shares corresponds to the set of stored random numbers;

generating a set of blinded passwords based on a common password and a set of blinded random numbers;

generating a set of passkeys based on the set of blinded passwords and the set of stored random numbers;

generating a set of decryption keys based on the set of blinded random numbers and the set of passkeys;

decrypting each encrypted share of the set of encrypted shares utilizing a corresponding decryption key of the set of decryption keys to produce a set of shares; and

decoding the set of shares to reproduce data.

7. The method of claim 6, wherein the generating the set of decryption keys comprises:

generating a set of values based on the set of blinded random numbers; and

generating the set of decryption keys based on the set of values and the set of passkeys.

8. The method of claim 7 further comprises:

for each blinded random number of the set of blinded random numbers, transforming the blinded random number utilizing a modulo function based on security parameters to produce a value of the set of values.

9. The method of claim 7, wherein the generating the set of decryption keys further comprises:

for each passkey of the set of passkeys, transforming the passkey utilizing a modulo function based on security parameters and a corresponding value of the set of values to produce a decryption key of the set of decryption keys.

10. The method of claim 6, wherein the retrieving the at least the decode threshold number of stored random numbers comprises at least one of:

outputting at least one stored random number retrieval request message to at least one dispersed storage (DS) processing unit to retrieve the at least the decode threshold number of stored random numbers from a dispersed storage network (DSN) memory; and

for each stored random number of the set of stored random numbers;

retrieving a set of encoded stored random number slices from the DSN memory; and

dispersed storage error decoding set of encoded stored random number slices to produce the stored random number.

11. The method of claim 6, wherein the retrieving the at least the decode threshold number of encrypted shares comprises at least one of:

outputting at least one encrypted share retrieval request message to at least one dispersed storage (DS) processing unit to retrieve the at least the decode threshold number of encrypted shares from a dispersed storage network (DSN) memory; and

for each encrypted share of the set of encrypted shares;

retrieving a set of encoded encrypted share slices from the DSN memory; and

dispersed storage error decoding set of encoded encrypted share slices to produce the encrypted share.

12. The method of claim 6 further comprises:

the generating the set of blinded random numbers including;

obtaining a set of base random numbers; and

expanding each base random number of the set of base random numbers based on security parameters to produce the set of blinded random numbers; and

the generating the set of blinded passwords including;

for each blinded random number of the set of blinded random numbers, transforming the common password utilizing a mask generating function and the blinded random number to produce a blinded password of the set of blinded passwords.

13. The method of claim 6, wherein the generating the set of passkeys comprises at least one of:

for each blinded password of the set of blinded passwords, transforming the blinded password utilizing a modulo function based on a corresponding stored random number of the set of stored random numbers and security parameters to produce a passkey of the set of passkeys; and

outputting the set of blinded passwords to a dispersed storage (DS) processing unit and receiving the set of passkeys.

14. The method of claim 6, wherein the decoding the set of shares to reproduce data comprises at least one of:

dispersed storage error decoding the set of shares to produce the data; and

decoding the set of shares utilizing a secret sharing function to produce the data.

15. A computer comprises:

an interface;

a memory; and

a processing module operable to;

apply a share encoding function on data to produce a plurality of encoded shares;

generate a corresponding plurality of random numbers for the plurality of encoded shares;

for each encoded share of the plurality of encoded shares;

generate an encryption key based on a common password and a corresponding one of the corresponding plurality of random numbers; and

encrypt the encoded share utilizing the encryption key to produce an encrypted share; and

facilitate storage of the corresponding plurality of random numbers and each of the encrypted shares.

16. The computer claim 15, wherein the share encoding function comprises at least one of:

a dispersed storage error encoding function; and

a secret sharing function.

17. The computer of claim 15, wherein the processing module further functions to generate the corresponding plurality of random numbers by:

obtaining a plurality of base random numbers; and

expanding each base random number of the plurality of base random numbers based on security parameters to produce the corresponding plurality of random numbers.

18. The computer of claim 15, wherein the processing module further functions to generate the encryption key by:

transforming the common password utilizing a mask generating function, security parameters, and the corresponding one of the corresponding plurality of random numbers.

19. The computer of claim 15, wherein the processing module functions to facilitate storage of the corresponding plurality of random numbers and the encrypted shares by at least one of:

sending, via the interface, the encrypted share and the corresponding one of the corresponding plurality of random numbers to a dispersed storage (DS) processing unit;

dispersed storage error encoding the encrypted share to produce a plurality of encoded share slices and outputting, via the interface, the plurality of encoded share slices for storage; and

dispersed storage error encoding the corresponding one of the corresponding plurality of random numbers to produce a plurality of encoded random number slices and outputting, via the interface, the plurality of encoded random number slices for storage.

20. A computer comprises:

an interface;

a memory; and

a processing module operable to;

retrieve, view the interface, at least a decode threshold number of stored random numbers to produce a set of stored random numbers;

retrieve, via the interface, at least a decode threshold number of encrypted shares to produce a set of encrypted shares, wherein the set of encrypted shares corresponds to the set of stored random numbers;

generate a set of blinded passwords based on a common password and a set of blinded random numbers;

generate a set of passkeys based on the set of blinded passwords and the set of stored random numbers;

generate a set of decryption keys based on the set of blinded random numbers and the set of passkeys;

decrypt each encrypted share of the set of encrypted shares utilizing a corresponding decryption key of the set of decryption keys to produce a set of shares; and

decode the set of shares to reproduce data.

21. The computer of claim 20, wherein the processing module further functions to generate the set of decryption keys by:

generating a set of values based on the set of blinded random numbers; and

generating the set of decryption keys based on the set of values and the set of passkeys.

22. The computer of claim 21, wherein the processing module further functions to:

for each blinded random number of the set of blinded random numbers, transform the blinded random number utilizing a modulo function based on security parameters to produce a value of the set of values.

23. The computer of claim 21, wherein the processing module further functions to generate the set of decryption keys by:

for each passkey of the set of passkeys, transforming the passkey utilizing a modulo function based on security parameters and a corresponding value of the set of values to produce a decryption key of the set of decryption keys.

24. The computer of claim 20, wherein the processing module functions to retrieve the at least the decode threshold number of stored random numbers by at least one of:

outputting, via the interface, at least one stored random number retrieval request message to at least one dispersed storage (DS) processing unit to retrieve the at least the decode threshold number of stored random numbers from a dispersed storage network (DSN) memory; and

for each stored random number of the set of stored random numbers;

retrieving, via the interface, a set of encoded stored random number slices from the DSN memory; and

dispersed storage error decoding set of encoded stored random number slices to produce the stored random number.

25. The computer of claim 20, wherein the processing module functions to retrieve the at least the decode threshold number of encrypted shares by at least one of:

outputting, via the interface, at least one encrypted share retrieval request message to at least one dispersed storage (DS) processing unit to retrieve the at least the decode threshold number of encrypted shares from a dispersed storage network (DSN) memory; and

for each encrypted share of the set of encrypted shares;

retrieving, via the interface, a set of encoded encrypted share slices from the DSN memory; and

dispersed storage error decoding set of encoded encrypted share slices to produce the encrypted share.

26. The computer of claim 20, wherein the processing module further functions to:

generate the set of blinded random numbers by;

obtaining a set of base random numbers; and

expanding each base random number of the set of base random numbers based on security parameters to produce the set of blinded random numbers; and

generate the set of blinded passwords by;

for each blinded random number of the set of blinded random numbers, transforming the common password utilizing a mask generating function and the blinded random number to produce a blinded password of the set of blinded passwords.

27. The computer of claim 20, wherein the processing module further functions to generate the set of passkeys by at least one of:

for each blinded password of the set of blinded passwords, transforming the blinded password utilizing a modulo function based on a corresponding stored random number of the set of stored random numbers and security parameters to produce a passkey of the set of passkeys; and

outputting, via the interface, the set of blinded passwords to a dispersed storage (DS) processing unit and receiving the set of passkeys.

28. The computer of claim 20, wherein the processing module functions to decode the set of shares to reproduce data by at least one of:

dispersed storage error decoding the set of shares to produce the data; and

decoding the set of shares utilizing a secret sharing function to produce the data.