Patent ID: 7941674

Claim:
A portable storage device comprising: an interface to a host device; and a storage medium including a first storage area associated with a first range of logical addresses and a second storage area associated with a second range of logical addresses, wherein the first storage area and the second storage area each comprise a respective sector 0, and wherein the first storage area comprises a clear user area and the second storage area comprises a secure storage area; wherein the portable storage device is operative to: offset a logical address received from the host device by an offset parameter to produce an offset logical address if the portable storage device is operating in a first mode of operation, wherein the logical address is outside of the second range of logical addresses and wherein the offset logical address is in the second range of logical addresses; offset the logical address received from the host device by a second offset parameter if the portable storage device is operating in a second mode of operation, wherein the logical address offset by the second offset parameter is in the first range of logical addresses; and transform the offset logical address to a physical address.