Let's suppose that you want to build some device that use FPGA/ASIC technology 
and your system should provide a certain level of security when dealing with data 
from external world. This means that some data should be somehow encrypted. 
Two important questions could appear in this stage: first, what encryption 
algorithm should we use and second, do we need a hardware implementation or software one? 
In this paper we will provide some answers, taking in consideration a real world application.