As we have seen all along this chapter, securing information traveling through communication channels is of primary importance...but what good does it do if all that is required to get a hold of that information is trivially obtained through physical access, i.e., a stolen laptop. Disk encryption lets you secure your data locally through the same powerful encryption algorithm as those used for secured communications.
This chapter introduces techniques and methods for local disk encryption. Among the many challenges are:
Data integrity
Performance penalty
Ease of use