How Quantum Computers Can Affect Bitcoin

This time is far from being the first one when bitcoin’s demise is predicted. MSN reports that the seven-year-old cryptocurrency has been proclaimed dead for more than 100 times! However, despite all pessimistic expectations and predictions a recent resurgence has resulted in a tripling in bitcoin’s price over the last year. For the time of its existence, bitcoin has survived price crashes, cyber heists and community infighting. Indeed, the cryptocurrency has one significant threat – quantum computers.

The first theory about quantum computers appeared in 1982 and only recently the theory has transformed into significant real-world advances, with such giants as Google, NASA and the CIA working towards building a quantum computer. Nowadays, the development of actual quantum computers is still in progress, but there have already been trials when quantum computational operations were executed on a very small number of quantum bits.

Multiple national governments and military agencies are investing in quantum computing research to adopt such computers for civilian, business, trade, environmental and national security purposes, such as cryptanalysis.

According to computer scientists, the era of new ultra-powerful quantum computers can cripple current encryption methods, collapse bitcoin’s technological foundations and finally result in the demise of the cryptocurrency.

“Bitcoin is definitely not quantum computer proof,” Andersen Cheng, co-founder of U.K. cybersecurity firm Post Quantum, said. “Bitcoin will expire the very day the first quantum computer appears.”

Cheng explains that bitcoin users have a public key and a private key. The recipient shares the public key with the sender to receive bitcoin, but he always needs his private unique key to spend the currency. If the private key gets known to a third party, they can spend all the bitcoin.

“If you have a quantum computer then you’re able to just basically calculate the private key from the public key,” says Martin Tomlinson, a professor in the Security, Communications and Networking Research Centre at Plymouth University. “It would take just a minute or two. So by learning all the private keys using a quantum computer, you’d have access to all the bitcoin that’s available.”

We don’t know when the first quantum computer capable of ruining bitcoin will appear. But judging by the investments in the sphere, it can happen soon. Earlier this year, the European Commission started a new €1 billion ($1.1 billion) project aimed at bringing about a “quantum revolution.”

There are companies that claim to have already built quantum computers. One of them is Canada’s D-Wave. However, Tomaso Calarco, director of Integrated Quantum Science and Technology, recently commented that “D-Wave’s machines are not recognized by the scientific community”. Ilyas Khan, co-founder of Cambridge Quantum Computing, though insists that it is “only a matter of relatively short time” before quantum technologies become of practical importance in the real world.

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