Codes, not ciphers

Abstract

This article is written as a companion piece to the recent account of cryptography in [1]. The aim will be similar—to explain the meaning and principles of coding, give some implementations that are feasible at school and early undergraduate level, and give a flavour of the types of mathematics involved.2. Cryptography and coding—What's the difference?Cryptography concerns the transmission of secret or sensitive information in such a way that if intercepted en route by an ‘enemy’, that enemy will be incapable of understanding it and therefore be prevented from using it for any political, financial, military or other advantage.