Crypto And Quantum Computing – is it a Threat?

Medium Juil 10, 2020

Crypto Quantum Computing
Key Takeaways:
– Quantum computing concerns new technology that would be able to process data much quicker than our current computers can
– There are two main thoughts on its implication on cryptocurrencies: some consider it a potential threat, while others believe crypto can adapt to it
– At any rate, quantum computing is still in its early stages. As such, it is too early to tell what its impact will actually be

Quantum computing sounds like a term straight out of science-fiction. Some even claim that it could pose a threat to cryptocurrencies. Today, we’re taking a closer look at what quantum computing is and how it could affect crypto.

What is Quantum Computing?

Quantum computing is a brand-new kind of computing, currently not seen in modern-day computers. The computers we know and love today process information based on bits. A bit can only hold one of the following two values: 0 or 1. These bits can be strung together to create a piece of binary code. For example, 1000101101 would be a valid piece of binary information. 8 Bits together are also known as bytes. You can read more about bits and how they work here

This standard of using bits has been pretty much around since computers existed. Quantum computing has decided to throw this formula upside down and create an entirely new system. Instead of using bits, quantum computing would be making use of so-called quantum bits, or qubits in short. This would allow it to process data in a way that’s vastly more efficient, making it much quicker.

Quantum technology is still very much at an early stage. Many errors remain while trying to reliably use quantum processing. As the Scientific American indicates, “A breakthrough is probably several years away”. However, the extremely efficient processing of data could hypothetically pose a threat to cryptography. 

The Two Schools of Thought on its Implications in Cryptocurrencies

As might be expected, cryptocurrencies rely heavily on cryptography. When it comes down to the introduction of quantum computing, the cryptocurrency community is a bit divided on its implications. There are basically two trains of thought in this, and we’d like to take a look into them here. Do note that all that is about to be discussed is currently still hypothetical. Quantum computers are pretty much non-existent at the time of writing, so we don’t fully know the exact implications it’ll have yet.

Dangerous by reverse engineering public and private key generation

Firstly, there’s the school of thought that quantum computing could pose a threat to the asymmetric cryptography which is used to generate your public key. To put it simply, there is the possibility that your public key’s generation could be reverse engineered via quantum computing. By doing this, the private key belonging to a certain address could hypothetically be obtained. Sure enough, this would majorly affect cryptocurrencies since the person holding the private keys can effectively control them.

Another aspect mentioned is that it could pose a threat to the mining protocol of  Proof-of-Work (PoW) blockchains, such as Bitcoin. This however, seems less likely. While the effect on asymmetric cryptography could be pretty huge, this is not so much the case for symmetric cryptography like hashing. “For hashing, the difference — while still enormous — is a lot less”, according to Cointelegraph. For another, the difficulty level of mining Bitcoin and other PoW blockchains would likely be able to adapt itself to the quantum era. 

Bitcoin and crypto can adapt

Speaking of adapting, the second school of thought on quantum computing’s effect on cryptocurrencies such as Bitcoin believe that these threats can be mitigated. Sure enough, almost all blockchains can undergo certain updates. Most of them do this through events called forks. Potentially, a fork could include countermeasures to mitigate threats that quantum computing could pose. Several blockchains have undergone many updates to tackle different issues – and quantum computing could be just another fork along this path.

Sure enough, the hypothetical threat that quantum computing could pose is already being looked into by many actors in the field. An example is the Nationwide Analysis Council (NRC) of Canada teaming up with the College of Waterloo to explore how to make blockchains quantum-safe. Famous Bitcoiner and author of The Internet of Money Andreas M. Antonopoulos mentions that Bitcoin could easily migrate to another algorithm.


At its current state, quantum computing is still in its early stages and is not likely to pose any threat yet. As Edward Felten, co-founder and chief scientist of Offchain labs told Finance Magnates: “today’s quantum computers exist only in the lab and are a long way from having practical impacts on cryptocurrencies”. While many hypotheses exist on it, it’s quite simply too early to tell what the impact will be. At any rate, the crypto community is keeping a close eye on quantum computing’s developments – Ledger included.

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