Introduction

In today's world of computers and digital communication, keeping information secure often comes down to number theory — and prime numbers sit right at the heart of that security. This chapter opens by looking closely at primes and the properties that make them so useful for encryption, before moving on to how numbers are represented in binary, the form computers actually work with. From there we introduce complex numbers and their basic properties, revisit logarithms and their real-life uses — from measuring earthquake intensity to computing lo …