why the quantum computer is a threat to bitcoin?

Reputed to be inviolable, bitcoin will have to be wary of the quantum computer in the years to come. Their computing power could undermine the security of the bitcoin network.

Bitcoin, and cryptocurrencies in general, have no shortage of enemies and a new threat is looming. Without repeating the whole story, it is important to remember that bitcoin is based on a technology called blockchain, which is reputed to be inviolable, or almost. Protected by the SHA-256 algorithm, it is now deemed safe and the main risks are to be found in safes or digital wallets. These are held by individuals and platforms.

With computers as we know them, cryptocurrency therefore has little to fear. But that could change with the arrival of quantum computers over the next decade, as scientists at the University of Sussex explain. They believe that these machines will probably be powerful enough to undermine the security that protects bitcoins.

The quantum threat hangs over Bitcoin

Led by Mark Webber, the scientists explain that each transaction is assigned a cryptographic key. The latter is vulnerable for a fixed period, which can vary between 10 minutes and an hour, or even a day. For researchers, a quantum computer with 1.9 billion qubits would be needed to “crack” a cryptographic key in 10 minutes. This power drops to 317 million qubits with a window of one hour and 13 million qubits to accomplish this task, provided you have a full day.

This threat must obviously be taken seriously for the years to come. However, this risk should be put into perspective, because we are far from developing such power. At present, and as Tom’s Hardware reminds us, the most powerful quantum computer – IBM’s Eagle – develops a power of 127 qubits. A promising record… and far from the power needed to undermine the security of bitcoin. Sussex scientists believe that at the current rate of progress, sufficiently powerful quantum computers will not see the light of day before “potentially more than a decade”. This puts us in the 2030s and allows time for the crypto community to organize itself.

Solutions exist to avoid the “quantum apocalypse”

While Google and IBM claim to have already achieved quantum supremacy, these works can be related to another: the quantum apocalypse. The BBC recently took up this question which worries some experts. “Quantum computers will make most existing methods of encryption useless. They are a threat to our way of life”, assures Ilyas Khan of Quantinuum. His colleague Harri Owen, from PostQuantum, agrees and explains:

“Everything we do today on the internet, whether it’s online shopping, banking transactions, interactions on social networks, is encrypted […] But as soon as a working quantum computer is able to break those keys… It can almost instantly create the ability for whoever developed it to empty bank accounts, completely collapse government defense systems – wallets in bitcoins will be emptied”.

If the risk is real, the time is not for alarmism and initiatives are emerging. In the UK, government data classified as “top secret” is already the “post-quantum” era. They benefit from a new form of security to resist possible attacks.

In addition to specialized companies, tech giants are also reacting and working on solutions. These operations have a significant cost, but the alternative solution which consists in “do nothing” is not an option, experts say.

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