Assessing Overhead Cost Associated with Encrypting Swap File

Privacy and security of information are two important concerns for most computer users. Passwords, keys, and encrypted information can be found unencrypted in the swap file which is used by the operating systems to support the implementation of virtual memory. Therefore, encrypting the swap file is essential to provide more security of users´ private and confidential information. However, encrypting the swap file comes with an extra overhead cost. In this paper, we measure the overhead cost associated with encrypting the swap file. To effectively measure this cost, we developed our own benchmarks that will enforce heavy swapping with disk write and read operations. We measured the overhead cost for Windows 7 operating system. In our measurements, we considered a number of popular encryption algorithms which include AES, Blowfish, Twofish, and GOST. Our experimental measurements show that Windows 7 incurs considerable overhead penalties when encrypting the swap file.