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Although Bitcoin boasts of being a very secure cryptocurrency, quantum computers could pose a threat. Today’s computers are too small, but how long before they can hack our transactions? A new study charts a hopeful timeline.

What began in 2009 as an experiment among a small group of people has grown into a globally popular phenomenon. The Bitcoin cryptocurrency is known for its trading perks – experiencing large drops often offset by huge rises, which are perfect for a GRID bot that invests automatically.

But what Bitcoin boasts about is its privacy. There is no need to share personal data or rely on the authority of any central bank: all you need to trade Bitcoins is a computer.

On its website, Bitcoin boasts of “taking one big step in monetary security”, claiming that Bitcoins “are impossible to counterfeit” and appealing to the proven track record of its technology. 

Nevertheless, is Bitcoin as secure as it promises? At a time when cyberattacks are already a weapon of war, it is more relevant than ever to ask whether our savings are vulnerable to such threats.

Mathematical Security

What distinguishes Bitcoin from other financial systems (such as the bank where we have our current account) is that it is a decentralized system. 

That is, its operation does not depend on any central authority. But otherwise, the level of security is comparable to that used by banks and armed forces to protect their data from prying eyes.

Security is actually based on mathematical problems that are so difficult, that it would take centuries for today’s most sophisticated computers to solve them.

But if the solution is known in advance, it is easy to verify that it actually solves the problem. Only those who can legitimately access the data know the solution, and for everyone else, the probability of guessing it is so remote that it is not even worth trying.

But is there a way to find these solutions faster? With the computers on the market, so far it has not been possible to find a way to speed up the process. 

However, it has been known for decades that quantum computers could solve such problems in record time.

The Quantum Threat

The quantum computers available today are still very limited and pose no threat to the security of cryptocurrencies, banks or the military.

So how long until current systems are no longer secure? A new study charts a hopeful timeline.

To give realistic figures, the paper takes into account an important factor in gauging the quantum threat: time. It takes between ten minutes and an hour from the time a transaction is sent to the time it becomes effective. 

If a computer takes longer to solve the mathematical problem needed to hack the transaction, it will be too late to intervene.

That is why the study asks what size of a quantum computer (measured in cubits, the basic unit in this type of computing) is needed to solve this mathematical problem in a maximum of one hour. 

The results are reassuring. According to the research team’s calculations, 317 million cubits are needed to solve the problem in one hour. If you want to solve it in ten minutes, you need 1.9 billion.

The size record is currently held by IBM, which in November 2021 announced that it had built a 127-cubit quantum computer. By 2023, they want to exceed 1,000, still far from the number needed to threaten security systems.

There is Time to Adapt

The authors of the study consider that it is “many years, possibly more than a decade” before quantum computers put Bitcoin in check. But the data should be interpreted with some caution.

As the authors themselves remind us, we cannot rule out the possibility that better mathematical tricks will be developed to solve this type of problem with fewer cubits. If that were to happen, security could be compromised sooner.

Another reason for caution comes from quantum error correction technology. By their very nature, cubits are very unstable, and many are needed to get quantum computers to operate reliably. 

The new study focuses on the most promising error-correction technique at present, according to the authors: the so-called “surface code.” But they admit that in the future, ways could be devised to achieve the same reliability with fewer cubits.

That’s why it’s time to think about alternative security systems that are not vulnerable to quantum computing. Fortunately, work is already underway to design and implement them, not only for Bitcoin but also for banks, the military, e-commerce, and the myriad of everyday situations that use these types of security systems.

Of course, not everything quantum poses a threat: the same study also analyzes the simulation of molecules that could help isolate nitrogen from the air to make fertilizers. 

The best supercomputers are incapable of tackling this problem, the solution to which could have a major impact on the world’s food shortages and the climate crisis.

According to the new study, 7.5 million cubits would be enough to simulate these molecules in about ten days. 

Although computers of this size are not yet within reach, advances in the next few years will be critical to achieving this number. The transformative potential of quantum computers could be just around the corner.

Conclusion

Bitcoin’s security depends on many factors, and this study looks at just one of them. As the cryptocurrency itself reminds us on its website, “the most common vulnerability is user failure”. 

In other words, quantum computers are not the main threat to your Bitcoins, neither now nor in a couple of decades. 

To keep your money safe it is essential that you take all the recommended security measures, such as keeping most of your savings off the internet, making an encrypted backup of your wallet and keeping your software always up to date.