Network Security

Hello! i am new here, i am a student of Shenyang university, i have some little problem to solve wchich i am needing someone help please, i am running a semester project now, wchich i finished everything but i am asked to change the function. my topic was to design a small system wchich can achieves some security's fuctions, i would be very glad if someone can assists me please, i shall post the full details of what i did for you to see if you are willing to help, thanks.