To save the tamper-proof ledger from quantum-enabled hackers, the two technologies will join forces. If they don’t, cybersecurity is vulnerable and data is at risk 

In the nineteenth century, there was a bitter war between the advocates of two competing forms of electricity – AC and DC – which became a heated rivalry full of misinformation.

Today, that conflict has echoes in the fierce debate between advocates of blockchain who believe it is secure and those who think it could be broken by new quantum computers

Thanks to the much-lauded tamper-proof construction of its ledger, blockchain is being integrated into everything from insurance to immigration and is, of course, the basis for cryptocurrencies such as Bitcoin.

But its open and versatile nature could be its undoing – in 2019, quantum computing could break the blockchain. 

Quantum computers can store more information using less energy than traditional computers, which means they can rapidly perform complex calculations.

Where a normal computer would solve a complex maze by going down one path at a time, quantum machines can go down multiple paths simultaneously.

As a result, quantum technology is estimated at being tens of thousands to millions of times faster than current computers – and more power means tasks such as breaking encryption becomes massively easier, potentially exposing financial records, personal data and other sensitive information.

In 2016, scientists at MIT and the University of Innsbruck successfully built a quantum computer that they claim could – if successfully scaled up – break RSA encryption, a widely used algorithm that secures everything from text messages to online shopping.

The blockchain is particularly vulnerable because it has a single point of failure – all the blocks are freely available for criminal organisations or surveillance operatives to gather.

Right now, they can’t do anything with them because they are encrypted, but when quantum computing gets cheap enough, there could be huge leaks of blockchain data that is potentially being stockpiled now.

It’s like keeping your valuables in a padlocked box but then leaving it out on the street

Quantum’s “entanglement” ability also enables it to make logical leaps conventional computers never would.

It could fill in the gaps between data harvested from just a few blocks

We’ve gone from theory and prototype to commercial quantum computing in just a few years.

In March 2018, Google unveiled Bristlecone, a chip with 72 qubits that the company believes could soon reach “quantum supremacy”, bringing mass-produced quantum computers to market.

The technology is being refined to create stable qubit processors and mega-qubit machines are months away.

The industry is concerned.

Each year, researchers from governments and computing giants including Intel, Microsoft and Cisco meet with top academics in the worlds of cybersecurity and mathematics at the Workshop on Quantum-Safe Cryptography to discuss potential solutions to the threat.

The nineteenth century current war was ended when the competing technologies of AC and DC were combined to allow the strengths of both to shine through.

The same collaborative approach is required today.

The technology to defend against quantum attacks already exists in the form of precursors to quantum-crypto such as hash-based cryptography, code-based cryptography, lattice-based cryptography, multivariate cryptography and super singular elliptic curve isogeny cryptography, each of which improves on previous iterations.

With increasing attacks on our personal data, such as the September 2018 British Airways hack, we need to push for collaboration between these seemingly competing technologies.

Although quantum computing seems to undermine the security of the blockchain, the answer could be to combine the two technologies and create a better whole.