Will Google’s ‘Quantum Supremacy’ Change the Future of Cryptocurrency?

It seems that the notion of using quantum computers in our everyday lives is getting closer and closer to reality.

Financial Times reported that the people at Google have obtained “quantum supremacy,” in the sense that they’ve constructed a quantum computer that is able to solve mathematical equations that seemed impossible before.

It will be so much faster that calculations that would take a computer a whole human lifespan to solve would be solved in a couple of seconds by a quantum computer.

If the aforementioned report is really true, this will be a big milestone in the development of quantum computers and possibly the end of the blockchain technology as we know it.

Of course, until something is announced the idea of a quantum computer is still theoretical.

A report from data research company CB Insights explained that quantum computers use “naturally occurring quantum-mechanical phenomena” – entanglement and superposition. As the report states:

“These states of matter, when harnessed for computing purposes, can speed up our ability to perform immense computations.”

Canada has also invested in research on the topic

The topic gravitating around quantum computers is interesting to many parties. For example, during the summer the National Research Council (NRC) of Canada worked together with the University of Waterloo in launching a research-initiative for quantum-safe blockchain technology.

Over the two-year research effort, which is led by Srinivasan Keshav and Michele Mosca, professors from the University of Waterloo, the team will receive a total of $180,000.

According to Nic Defalco, communications advisor to the NRC, the sum will be used to hire more “highly qualified personnel”.

This is no coincidence as according to the CEO of quantum R&D firm Post-Quantum, Andersen Cheng, Canada is investing the most when it comes to quantum computing research. He continued:

“Other governments are trying to play catch-up… The U.S. is lagging behind quite a bit. The UK is putting a lot of money into quantum computing hardware and now, they’re just about to start thinking about post-quantum software and cryptography.”

So why all the commotion?

CB Insights note that the efforts in the private sector have also increased recently. For example, the number of private sector investments in quantum computing startups has increased by 200% in the last six months.

Adam Koltun, part of the Quantum Resistant Ledger (QRL) Foundation commented on this movement:

“A decade ago people said it would take 50 years to get where we are now with quantum computing. Five years ago, they said it would take 25 years to get where we are now. So quantum computing has this nasty habit of exceeding people’s expectations.”

According to him: 

“The blockchain industry does need to grapple with this and be wary.”

Koltun is afraid that the future blockchain and cryptocurrencies will be at risk if proactive behavior to safeguard the current technology doesn’t appear soon.

It’s all about caution

There are some ways for a quantum computer to break a blockchain. For example, the elliptic curve cryptography (ECC) that is the base of the digital signatures that secure a blockchain transaction is not that “quantum-safe”, according to Cheng.

Theoretically, a quantum computer could be able to decrypt user private keys and produce signatures on behalf of the users.

The more important thing to Cheng is that: “Once that trust is broken, that will be the end of cryptocurrencies,” adding that:

“If you can no longer tell whether [the right] people are signing transactions to you or not, then you have destroyed trust. This cryptocurrency world is based on a distributed, trustless environment.”

The more worrying part is that, even now, mathematicians already know an algorithm (Shor’s algorithm) that could possibly crack elliptic curve digital signatures when used by a quantum computer.  

There is another possibility, as Koltun noted, that when quantum computers become a reality they may actually exceed our expectations in terms of performance and totally outrun blockchain technology. According to him:

“You should be wary of anyone who claims to sell you a waterproof watch or quantum-proof blockchain because we are not yet fully aware of the potential of quantum computers. … For someone to proclaim any technological product, blockchains or otherwise, as impervious to quantum computers would require them to know what these computers are entirely capable of, which we don’t.”

Against the invisible enemy

All this speculation is happening because we are still trying to fight an enemy that doesn’t exist. Scientists are still not aware of the actual capabilities of quantum computers and what their impact on blockchain technology may be.

On the other hand respected people like bitcoin evangelist and author Andreas M. Antonopoulos think that this quantum threat is a bit exaggerated:

During one of his monthly Q&As he noted:

“We can migrate quite easily to another algorithm… It’s not really as big a threat as people think it is.”

On the other hand, even the capabilities of quantum computers may be overemphasized. As Peter Todd shared:

It means nothing because Google's quantum breakthrough is for a primitive type of quantum computing that is nowhere near breaking cryptography.

We still don't even know if it's possible to scale quantum computers; quite possible that adding qbits will have an exponential cost. https://t.co/wSmO6ycaJk

— Peter Todd (@peterktodd) September 24, 2019

But even if there is a slight possible threat, professor Keshav at the University of Waterloo asks:

“Shouldn’t we be doing something about it today?”

Keshav and his team will research the most encouraging “quantum-safe cryptography” tools like multivariate public-key cryptography and lattice-based cryptography. Testing will be carried on Hyperledger Fabric and we can only hope that their research will lead to a successful result.