The larger the numbers, the safer the encryption. The first ingredient required for the algorithm are two large prime numbers. The system they developed allows for the secure transmission of information – such as credit card numbers – online.

In 1978, Ron Rivest, Adi Shamir and Leonard Adleman combined some simple, known facts about numbers to create RSA. One of the most widely used applications of prime numbers in computing is the RSA encryption system. We need to know about the properties of different numbers so that we can not only keep developing the technology we rely on, but also keep it secure. You may be wondering, if the number stretches to more than 23m digits, why we need to know about it? Surely the most important numbers are the ones that we can use to quantify our world? That’s not the case. The number, simply written as 2⁷⁷²³²⁹¹⁷-1 (two to the power of 77,232,917, minus one) was found by a volunteer who had dedicated 14 years of computing time to the endeavour. By comparison, the number of atoms in the entire observable universe is estimated to have no more than 100 digits. Stretching to 23,249,425 digits, it is so large that it would easily fill 9,000 book pages. They are a mathematical mystery, the secrets of which mathematicians have been trying to uncover ever since Euclid proved that they have no end.Īn ongoing project – the Great Internet Mersenne Prime Search – which aims to discover more and more primes of a particularly rare kind, has recently resulted in the discovery of the largest prime number known to date. Prime numbers are more than just numbers that can only be divided by themselves and one.