The Math Missus Sarah Smellie shows us how prime numbers keep our online shopping safe from cyber thieves and super spies.

Their result – that infinitely many primes can be expressed as p² + 4q², with both p and q prime – builds a bridge between classical number theory and new-age combinatorics.

Prime numbers are found hidden in nature, but humans have made spectacular use of them, writes mathematician Marcus du Sautoy. Ever since humans evolved on this planet we have been trying to make ...