Securing data in a dispersed storage network using security sentinel value

• US 8,601,259 B2
• Filed: 04/14/2010
• Issued: 12/03/2013
• Est. Priority Date: 04/20/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Resch, Jason K.
• Primary Examiner(s): Pwu, Jeffrey
• Assistant Examiner(s): Anderson, Michael D
• Application Number:
  US12/760,066
• Publication Number:
  US 20100268938A1
• Time in Patent Office: 1,329 Days
• Field of Search: 713/153, 713/160, 380/4, 380/40
• US Class Current: 713/153
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/0897 involving additional devices, e.g. trusted platform module [TPM], smartcard or USB
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions

Abstract

A sentinel value is combined with a data segment, and encrypted. A digest of the encrypted combined data segment is calculated, and used in conjunction with an encryption key to generate a masked key. This masked key is then appended to the encrypted combined data segment and transmitted to an encoder. When the data segment is retrieved, the original encryption key can be recovered and used to decrypt the data segment. The sentinel value can then be extracted from the data segment and checked for integrity. The data segment can then be delivered, discarded, flagged, or otherwise handled based on the integrity of the sentinel value.

Claims

1. A method for use in a pre-data manipulator of a computing device, the method comprising:

receiving a data segment at the pre-data manipulator;

combining the data segment with a sentinel value to generate a combined data segment, wherein the sentinel value is based on one or more of;

a security parameter associated with a user vault, a dispersed storage network (DSN)-wide security parameter, a unique number associated with the data segment, and an encrypted number;

encrypting the combined data segment using an encryption key to generate an encrypted combined data segment;

calculating a digest of the encrypted combined data segment;

encrypting the encryption key using the digest to produce a masked key;

appending the masked key to the encrypted combined data segment to generate an encrypted package; and

transmitting at least some of the encrypted package to an encoder.

2. The method of claim 1, further comprising:

selecting the encryption key based on one or more of;

the security parameter associated with the user vault and the DSN-wide security parameter.

3. The method of claim 1, further comprising:

pre-encrypting the data segment using a private key associated with the pre-data manipulator prior to combining the data segment with the sentinel value.

4. The method of claim 1, further comprising:

removing a portion of the encrypted package;

storing the portion in a data store; and

transmitting, as the at least some of the encrypted package, the encrypted package less the portion.

5. The method of claim 4, further comprising:

padding the at least some of the encrypted package to replace the portion of the encrypted package.

6. The method of claim 4, further comprising;

determining a size of the portion and a location of the portion within the encrypted package.

7. A method for use in a pre-data de-manipulator of a computing device, the method comprising:

receiving an encrypted package from a decoder;

separating the encrypted package into a masked key and an encrypted data segment;

calculating a digest of the encrypted data segment;

decrypting the masked key using the digest to produce a recovered encryption key;

decrypting the encrypted data segment using the recovered encryption key to generate a recovered data segment and a recovered sentinel value, wherein a sentinel value is based on one or more of;

a security parameter associated with a user vault, a dispersed storage network (DSN)-wide security parameter, a unique number associated with a data segment, and an encrypted number;

verifying the recovered sentinel value corresponds to the sentinel value; and

outputting the recovered data segment as the data segment when the recovered sentinel value corresponds to the sentinel value.

8. The method of claim 7, further comprising:

discarding the recovered data segment when the recovered sentinel value does not correspond to the sentinel value; and

generating a flag indicating that the recovered data segment is unreliable.

9. The method of claim 7, further comprising:

prior to separating the encrypted package;

determining that a portion of the encrypted package was withheld;

obtaining the portion; and

reinserting the portion into the encrypted package prior to.

10. The method of claim 7, further comprising:

prior to separating the encrypted package;

determining that a portion of the encrypted package was withheld;

sending a request to receive the portion;

receiving an unfavorable response to the request; and

determining that the encrypted package is unrecoverable based on the unfavorable response.

11. The method of claim 7, further comprising:

prior to separating the encrypted package;

determining that a portion of the encrypted package was withheld;

sending a request to receive the portion;

failing to receive a response to the request within a threshold amount of time; and

marking the encrypted package as unavailable based on the failing to receive a response.

12. The method of claim 7, wherein the outputting the recovered data segment comprising:

decrypting the recovered data segment using a private key associated with the pre-data de-manipulator prior to outputting.

13. A pre-data manipulator comprising:

processing circuitry to;

combine a data segment with a sentinel value to generate a combined data segment, wherein the sentinel value is based on one or more of;

a security parameter associated with a user vault, a dispersed storage network (DSN)-wide security parameter, a unique number associated with the data segment, and an encrypted number;

encrypt the combined data segment using an encryption key to generate an encrypted combined data segment;

calculate a digest of the encrypted combined data segment;

encrypt the encryption key using the digest to produce a masked key;

append the masked key to the encrypted combined data segment to generate an encrypted package; and

an output to transmit at least some of the encrypted package to an encoder.

14. The pre-data manipulator of claim 13, further comprising:

the processor further to select the encryption key based on one or more of;

the security parameter associated with the user vault and the DSN-wide security parameter.

15. The pre-data manipulator of claim 13, further comprising:

the processor further to pre-encrypt the data segment using a private key associated with the apparatus prior to combining the data segment with the sentinel value.

16. The pre-data manipulator of claim 13, further comprising:

the processor further to;

remove a portion of the encrypted package;

store the portion in a data store; and

transmit, as the at least some of the encrypted package, the encrypted package less the portion.

17. The pre-data manipulator of claim 16, further comprising:

the processor further to pad the at least some of the encrypted package to replace the portion of the encrypted package.

18. The pre-data manipulator of claim 16, further comprising:

the processor further to determine a size of the portion to be removed and a location of the portion within the encrypted package.

19. A pre-data de-manipulator comprising:

processing circuitry to;

separate the encrypted package into a masked key and an encrypted data segment;

calculate a digest of the encrypted data segment;

decrypt the masked key using the digest to produce a recovered encryption key;

decrypt the encrypted data segment using the recovered encryption key to generate a recovered data segment and a recovered sentinel value, wherein a sentinel value is based on one or more of;

a security parameter associated with a user vault, a dispersed storage network (DSN)-wide security parameter, a unique number associated with a data segment, and an encrypted number;

verify the recovered sentinel value corresponds to the sentinel value; and

an output to provided the recovered data segment as the data segment when the recovered sentinel value corresponds to the sentinel value.

20. The pre-data de-manipulator of claim 19, further comprising:

the processing circuitry to;

discard the recovered data segment when the

recovered sentinel value does not correspond to the sentinel value; and

generate a flag indicating that the recovered data segment is unreliable.

21. The pre-data de-manipulator of claim 19, further comprising:

the processing circuitry to;

prior to separating the encrypted package;

determine that a portion of the encrypted package was withheld;

obtain, via an input, the portion; and

reinsert the portion into the encrypted package.

22. The pre-data de-manipulator of claim 19, further comprising:

the processing circuitry to, prior to separating the encrypted package;

determine that a portion of the encrypted package was withheld;

send, via a communication interface, a request to receive the portion;

receive, via the communication interface, an unfavorable response to the request; and

determine that the encrypted package is unrecoverable based on the unfavorable response.

23. The pre-data de-manipulator of claim 19, further comprising:

the processing circuitry to prior to separating the encrypted package;

determine that a portion of the encrypted package was withheld;

send, via a communication interface, a request to receive the portion;

determine that a response to the request was not received within a threshold amount of time; and

mark the encrypted package as unavailable.

24. The pre-data de-manipulator of claim 19, further comprising:

a decryption engine to decrypt the recovered data segment using a private key prior to the output providing the recovered data segment.