In this paper LVCMOS, HSLVDCI, HSTL, LVDCI_DV2 and SSTL Input/output standard is used for the design of Green Fibonacci generator on 40nm FGPA to generate key for Wi-Fi Protected Access in order to make energy efficient communication. In naming convention of I/O standard, LV is low voltage, HS is high speed, DV2 is half impedance, CMOS is Complementary metal Oxide Semiconductor, DCI is digitally control impedance and SSTL is Stub series Transistor Logic. Here we used two frequencies ranging i.e. 1GHz and 10 GHz. After comparison it is observed that, LVDCI-DC2 is the most energy efficient and SSTL15 is the worst energy efficient on 1GHZ frequency where as SSTL15 and HSTL outperforms better on frequency range 10GHz. There is reduction in I/O power requirement of LVDCI is19.19% as compared to SSTL15 and SSTL15 shows 17.60 % reduction in energy on 10GHz as compared to LVDCI-DC2.