A bidirectional wavelength division multiplexed Passive Optical Network (PON) has been proposed in which downstream Differential Phase Shift Keying (DPSK) signal is used for upstream On Off Keying (OOK) signal demodulation. This proposed passive optical network architecture is capable to support the high bandwidth requirements for present applications such as video conferencing, online gaming, telemedicine ...

Message authentication is one of the most effective ways to thwart unauthorized and corrupted messages from being forwarded in Wireless Sensor Networks (WSNs). For this reason, many message authentication schemes have been developed, based on either symmetric key cryptosystems or public-key cryptosystems. Most of them, however, have the limitations of high computational and communication overhead ...