10. The computer-readable storage medium of claim 9 , further comprising instructions for: determining a hierarchy amongst the logical partitions; and storing index information including the determined hierarchy; wherein the eReader device is further adapted to identify one or more logical partitions corresponding to the identified one or more encrypted segments, identify a hierarchy amongst the identified one or more logical partitions and, responsive to receiving the search query, display the identified hierarchy.
9. The computer-readable storage medium of claim 8 , further comprising instructions for: determining a mapping between the plurality of encrypted segments and the logical partitions of the e-book indicating the logical partitions of the e-book within each encrypted segment; and storing index information including the determined mapping between the plurality of encrypted segments and the logical partitions of the e-book.