Consolidating encrypted image backups without decryption

1. A method for consolidating encrypted image backups without decryption, the method comprising:

individually encrypting, using a single encryption key, each block in a first set of blocks in a source storage at a first point in time, each of the blocks in the first set of blocks corresponding to a unique block position in the source storage;

storing the first set of encrypted blocks in a first encrypted image backup;

individually encrypting, using the single encryption key, each block in a second set of blocks in the source storage at a second point in time, at least one of the blocks in the second set of blocks corresponding to the same block position in the source storage as one of the blocks in the first set of blocks;

storing the second set of encrypted blocks in a second encrypted image backup;

creating a consolidated encrypted image backup that includes a single encrypted block for each of multiple unique block positions represented by the first and second sets of encrypted blocks without decrypting any of the encrypted blocks; and

restoring the consolidated encrypted image backup to a restore storage.

2. The method as recited in claim 1 , wherein at least one of the first and second encrypted image backups is an encrypted incremental image backup.

3. The method of claim 1 , wherein at least one of the first and second encrypted image backups is an encrypted decremental image backup.

4. The method of claim 1 , wherein each block in the source storage is a cluster or a sector of the source storage.

5. The method of claim 1 , wherein the first and second sets of encrypted blocks are encrypted using a single encryption key.

6. The method of claim 5 , wherein the creating of the consolidated encrypted image backup is performed without using the single encryption key.

7. The method of claim 1 , wherein each encrypted block in the first and second sets of encrypted blocks is individually encrypted using a salt which is associated with a unique block position in the source storage represented by the encrypted block.

8. The method of claim 1 , wherein:

the encrypting of the first set of blocks and the second set of blocks is performed at the source storage;

the creating of the consolidated encrypted image backup is performed at a third-party storage;

the single encryption key is stored at the source storage; and

the single encryption key is not stored at the third-party storage.

9. The method of claim 1 , wherein the restoring of the consolidated encrypted image backup to the restore storage includes:

copying each encrypted block from the consolidated encrypted image backup;

decrypting each of the copied encrypted blocks; and

storing each decrypted block in a corresponding unique block position in the restore storage.

10. The method of claim 1 , wherein the restoring of the consolidated encrypted image backup to the restore storage includes:

copying each encrypted block from the consolidated encrypted image backup;

storing each of the copied encrypted blocks in a corresponding unique block position in the restore storage; and

decrypting at least some of the encrypted blocks stored in the restore storage.

11. One or more non-transitory computer-readable media storing one or more programs that are configured, when executed, to cause one or more processors to execute a method for consolidating encrypted image backups without decryption, the method comprising:

individually encrypting, using a single encryption key, each block in a first set of blocks in a source storage at a first point in time, each of the blocks in the first set of blocks corresponding to a unique block position in the source storage;

storing the first set of encrypted blocks in a first encrypted image backup;

individually encrypting, using the single encryption key, each block in a second set of blocks in the source storage at a second point in time, at least one of the blocks in the second set of blocks corresponding to the same block position in the source storage as one of the blocks in the first set of blocks;

storing the second set of encrypted blocks in a second encrypted image backup;

creating a consolidated encrypted image backup that includes a single encrypted block for each of multiple unique block positions represented by the first and second sets of encrypted blocks without decrypting any of the encrypted blocks; and

restoring the consolidated encrypted image backup to a restore storage.

12. A method for consolidating encrypted image backups in an image backup chain without decryption, the method comprising:

individually encrypting, at a source storage and using a single encryption function and a single encryption key accessible to the source storage, each block in a first set of blocks in the source storage at a first point in time, each of the blocks in the first set of blocks corresponding to a unique block position in the source storage;

storing the first set of encrypted blocks in a first encrypted image backup in an image backup chain;

individually encrypting, using the single encryption function and the single encryption key, each block in a second set of blocks in the source storage at a second point in time, at least one of the blocks in the second set of blocks corresponding to the same block position in the source storage as one of the blocks in the first set of blocks;

storing the second set of encrypted blocks in a second encrypted image backup in the image backup chain; and

creating, at a third-party storage that does not have access to the single encryption key, a consolidated encrypted image backup in the image backup chain that includes a single encrypted block for each of multiple unique block positions represented by the first and second sets of encrypted blocks without decrypting any of the encrypted blocks.

13. The method as recited in claim 12 , wherein:

the first encrypted image backup is an encrypted full image backup or an encrypted incremental image backup; and

the second encrypted image backup is an encrypted incremental image backup.

14. The method as recited in claim 13 , wherein:

the encrypted full image backup has a ShadowProtect Full (SPF) image backup format; and

the encrypted incremental image backup has a ShadowProtect Incremental (SPI) image backup format.

15. The method as recited in claim 12 , wherein:

the first encrypted image backup is an encrypted decremental image backup; and

the second encrypted image backup is an encrypted decremental image backup or an encrypted full image backup.

16. The method of claim 12 , wherein each block in the source storage is a cluster or a sector of the source storage.

17. The method of claim 12 , wherein each encrypted block in the first and second sets of encrypted blocks is individually encrypted using a salt which is associated with a unique block position in the source storage represented by the encrypted block.

18. The method of claim 12 , wherein the single encryption function is an Advanced Encryption Standard (AES)-128, an AES-160, an AES-192, an AES-224, an AES-256, a Blowfish, a Twofish, a Threefish, or a Serpent encryption function.

19. The method of claim 12 , further comprising restoring the consolidated encrypted image backup to a restore storage by:

copying each encrypted block from the consolidated encrypted image backup;

storing each encrypted block in a corresponding unique block position in the restore storage; and

decrypting at least some of the encrypted blocks either before or after the storing of the blocks in the restore storage.

20. One or more non-transitory computer-readable media storing one or more programs that are configured, when executed, to cause one or more processors to execute a method for consolidating encrypted image backups in an image backup chain without decryption, the method comprising:

individually encrypting, at a source storage and using a single encryption function and a single encryption key accessible to the source storage, each block in a first set of blocks in the source storage at a first point in time, each of the blocks in the first set of blocks corresponding to a unique block position in the source storage;

storing the first set of encrypted blocks in a first encrypted image backup in an image backup chain;

individually encrypting, using the single encryption function and the single encryption key, each block in a second set of blocks in the source storage at a second point in time, at least one of the blocks in the second set of blocks corresponding to the same block position in the source storage as one of the blocks in the first set of blocks;

storing the second set of encrypted blocks in a second encrypted image backup in the image backup chain; and

creating, at a third-party storage that does not have access to the single encryption key, a consolidated encrypted image backup in the image backup chain that includes a single encrypted block for each of multiple unique block positions represented by the first and second sets of encrypted blocks without decrypting any of the encrypted blocks.