All numbers can be broken down into their prime factors JV Photo/Alamy

Quantum computers could one day threaten the safety of the internet by breaking encryption – and now they are a step closer.

A quantum computing start-up company called Zapata has worked with IBM to develop a new way to factor large numbers, using it on the largest number that has been factored with a quantum computer so far. The team found that 1,099,551,473,989 is equal to 1,048,589 multiplied by 1,048,601.

The future success of the algorithm used could have big implications …