Introduction to Cryptography with Coding Theory, 3rd Edition

24.1 Introduction

All communication channels contain some degree of noise, namely interference caused by various sources such as neighboring channels, electric impulses, deterioration of the equipment, etc. This noise can interfere with data transmission. Just as holding a conversation in a noisy room becomes more difficult as the noise becomes louder, so too does data transmission become more difficult as the communication channel becomes noisier. In order to hold a conversation in a loud room, you either raise your voice, or you are forced to repeat yourself. The second method is the one that will concern us; namely, we need to add some redundancy to the transmission in order for the recipient to be able to reconstruct the message. In the following, ...