Quantum computers have been around for quite some time now, and their potential to perform mind-numbingly fast calculations is no secret to the scientific community. The problem, however, is scaling these calculations up to a commercially viable state.

One such popular example is Shor’s algorithm. Developed by Peter Shor in 1994, this quantum computing algorithm is used for factoring a number N in O((log N)3) time and O(log N) space. If all of that sounded like gibberish, fear not. In simple terms, Shor’s algorithm gives one the ability to factorise a large number N into its prime factors very efficiently.

Now how does this quantum algorithm affect us in our daily lives? And more specifically, how does it impact our data privacy and security? The answer lies in the manner of securing our data. Most encryption protocols use what is known as asymmetric encryption, where a public key is used to encrypt data, and a private key is used to decrypt the data. And the two keys are linked by a mathematical relationship. And yes, in case you were wondering, it involves factorisation. Popular asymmetric encryption methods such as RSA would be rendered obsolete if quantum computing took over.

But as we saw in the previous article, the problem with quantum computers is that of scale. Shor’s algorithm would require roughly a BILLION qubits to accurately crack the 2048 bit RSA encryption. Scientists have been trying desperately to reduce this number, for the current generation of quantum computers run on barely 50 qubits. It took scientists nearly 7 years to implement Shor’s algorithm, when IBM scientists successfully factorized 15, yes 15, into 3 and 5 with 7 qubits. Sounds like something a 7-year-old could do out of the top of their head, doesn't it?

This was until 2019 when scientists managed to bring down the 1 billion qubit number down to 20 million qubits, a significant leap forward in the field of quantum computing. They demonstrated the possibility of cracking the 2048 bit RSA encryption in 8 hours. Yes, it is still an enormous number, but it stands testament to the fact that the scientific community has come a long way indeed.

And added to this is the fact that there isn’t a Moore’s law equivalent to quantum computers, making this advancement all the more impressive. The potential for quantum computers looks bright, and the race to achieve quantum supremacy is very much on.

Written by Shrenik Kalambur, Head of Research at MIST