Patent ID: 7849514

Claim:
A system configured to secure data comprising: (A) a centralized device permission store in a computer memory configured to store: (i) a device identifier associated with a previously-registered mass storage device; (ii) a list of users authorized to use the previously-registered mass storage device; and (iii) a first publicly encrypted symmetric key of a first symmetric cipher associated with the previously-registered mass storage device; (B) a helper module in operative communication with the centralized device permission store, wherein the helper module is configured to: (i) receive the first publicly encrypted symmetric key from the centralized device permission store; (ii) obtain a second private key of a first user contained on the list of users, wherein the second private key is configured to decrypt the first publicly encrypted symmetric key; (iii) receive from an unregistered mass storage device an imported encrypted symmetric key of a second symmetric cipher that is different from the first symmetric cipher; (1) wherein the imported encrypted symmetric key is encrypted by a pass phrase; and (iv) receive the pass phrase from a second user associated with the unregistered mass storage device; and (C) a protection module in operative communication with the centralized device permission store and with the helper module, wherein the protection module is configured to: (i) intercept a first block to be written to the previously-registered mass storage device, and encrypt the first block using the first symmetric cipher, wherein the first symmetric cipher preserves the size of data blocks on the previously-registered mass storage device; (ii) intercept a second block read from the previously-registered mass storage device, and decrypt the second block using the first symmetric cipher, wherein the first symmetric cipher preserves the size of data blocks on the previously-registered mass storage device; (iii) intercept a third block to be written to the unregistered mass storage device, and encrypt the third block using the second symmetric cipher, wherein the second symmetric cipher preserves the size of data blocks on the unregistered mass storage device; and (iv) intercept a fourth block read from the unregistered mass storage device, and decrypt the fourth block using the second symmetric cipher, wherein the second symmetric cipher preserves the size of data blocks on the unregistered mass storage device.