The aessafe module implements the AES algorithm completely in software without using any table
lookups or other timing dependant mechanisms. This module actually contains two seperate
implementations - an implementation that works on a single block at a time and a second
implementation that processes 8 blocks in parallel. Some block encryption modes really only work if
you are processing a single blocks (CFB, OFB, and CBC encryption for example) while other modes
are trivially parallelizable (CTR and CBC decryption). Processing more blocks at once allows for
greater efficiency, especially when using wide registers, such as the XMM registers available in
x86 processors.