Quantum Computing Won’t Kill The Blockchain

Quantum computing has been in the news a lot lately. Most recently, Google announced that it has achieved quantum supremacy — the ability to perform calculations of immense complexity with tremendous speed. To illustrate what this means, Google says its quantum computer performed a task in 200 seconds that would have taken the world’s most advanced conventional supercomputer over 10,000 years.

Naturally, this has spurred much reaction, both from excited supporters and members of the scientific community who have compared it to the Wright brothers’ first flight, and from detractors who claim Google is exaggerating its accomplishment. It even set off a rare intra-industry war of words, with IBM accusing its competitor of grossly overstating the importance of its achievement. Exaggerated or not, Google’s announcement is significant as it relates to quantum computing generally. This technology will, sooner or later, come into the mainstream, with major implications across the technology sector.

The topic of quantum computing is of particular interest in another corner of the emerging technology universe: the blockchain community. And seemingly with good reason. Many people believe the advent of quantum computing will render blockchains obsolete. The security of blockchains is premised on the difficulty of solving their underlying math. Therefore, a quantum computer capable of lightspeed calculations might seem to pose an existential threat. After all, if there is a computer that can guess every possible 1,000-digit combination in a minute, the technical underpinning of blockchain could crumble. For those excited by the game-changing potential of blockchain technology in industries from financing to supply chain to IoT, this threat could be catastrophic.

But the naysayers are wrong. The simple fact of achieving quantum supremacy does not mean that Google or any individual or corporation can now overpower a blockchain. In fact, from a technical perspective, the short-term implications of Google’s breakthrough are modest. Nevertheless, the blockchain community should be aware of the progress being made on quantum computers. As the technology improves, blockchains will have to keep pace to avoid being overtaken. There are a few things blockchain and its supporters should begin working on immediately to stay ahead of the quantum threat.

The first is a process, already initiated by the National Institute of Standards and Technology (NIST), of standardizing “quantum-resistant” cryptography. Developing and implementing capabilities specifically designed to resist quantum computers will be key for the future of blockchains, as well as their survival. Blockchain supporters and developers should therefore closely monitor the standardization process and prepare to integrate the results into existing and future blockchain projects.

The second capability for blockchain enthusiasts to focus on is known as cryptographic agility. This concept is highly technical, but essentially refers to the ability of developers to improve a blockchain so that quantum-resistant features can be put in place after the network is operational. Given the number of projects being built on existing blockchains like Ethereum, their capacity to upgrade their own components in an ongoing way will be crucial.

The third area in need of attention is blockchain governance. This has been a topic of vigorous discussion and debate since the advent of blockchains. Due to the uncertainty around when quantum computers will be built at scale, blockchain projects must establish procedures to determine when and how to implement “quantum-safe” upgrades to their networks. This may prove to be the greatest challenge of all, given how difficult optimal governance has been for blockchains to date. It is critical that people across the crypto space begin seriously thinking and experimenting with ways to ensure governance is not a hindrance to the improvement of technology.

There is no doubt that quantum computing is coming, and it will have major effects across the technology space. But those who believe that its simple existence is a death knell for blockchain fail to consider that the latter will grow and evolve alongside quantum computing. There is much that can be done to make blockchains more dynamic and robust -- and if we do those things, we will not have to worry about quantum supremacy any time soon.

(Xinxin Fan is head of Cryptography of IoTeX, a technology company that uses blockchain, secure hardware, and trusted computing to build end-to-end encrypted device ecosystems for the Internet of Trusted Things.)