A Review paper on Data Communication System

Abstract

In these days, the communication technology is very vast. There are various type of communication technologies are available to transmission of information between sender and receiver and when information is transmitted from sender side to receiver it can be hacked by unauthorized person so Data security is also an important issue. In this paper we present different communication technology such as wired (use of a physical cable to transfer information between device like LAN, MAN etc), wireless (use of infrared or radio frequency signals to share information between devices like wi-fi, li-fi etc.) and a hierarchy of network security techniques such as: Secrecy, Authentication, Non-repudiation and Integrity control thought two popular security mechanisms, namely Cryptography and Steganography. These two security mechanism are well known and widely used technologies. Cryptography is used, when data is sent in encrypted form with using the encryption key and for hiding the data into another cover media, steganography is used.