Quantum computing could break bitcoin's encryption
Quantum computers could signal the end of bitcoin and other digital currencies, according to Andersen Cheng, co-founder of Post Quantum. He said a quantum computer would be capable of rapidly solving the private keys at the heart of bitcoin's encryption, allowing it to take control of the digital currency. Cryptographers are already working on new solutions to "quantum-proof" bitcoin, however, achieving consensus from the bitcoin community could prove to be a major stumbling block.

Some computer scientists say quantum computers are moving closer to reality and will cripple bitcoin’s encryption systems and doom bitcoin. Governments are investing aggressively in ...

prototype of quantum processor

Some computer scientists say quantum computers are moving closer to reality and will cripple bitcoin’s encryption systems and doom bitcoin. Governments are investing aggressively in quantum computers, which are ultra powerful.

Quantum computers, first theorized by physicist Richard Feynman in 1982, have promised a new era of computing. The theory has only recently translated into significant real-world advances, with NASA, the CIA and Google working on a quantum computer. Computer scientists now warn the machines will cripple existing encryption methods and destroy bitcoin’s technological foundations.

The End Of Bitcoin?

Andersen Cheng, co-founder of Post Quantum, a U.K. cybersecurity firm, told Newsweek that bitcoin will end the day the first quantum computer arrives. He said the quantum computer will undermine the cryptography surrounding bitcoin’s public and private keys.

Bitcoin recipients share their public key with the sender. To spend bitcoin, a bitcoin owner must use their private key. If another party learns the private key, that party can spend all the bitcoin.

Martin Tomlinson, a professor at the Security, Communications and Networking Research Centre in Plymouth University, said a quantum computer can calculate the private key from the public one in a minute or two. By learning all the private keys, someone would have access to all available bitcoin.

Tomlinson did not know when the first quantum computer will appear that will have this capability, but he noted that extensive research is under way. The European Commission announced a $1.1 billion project earlier this year aimed at bringing a “quantum revolution.”

How Close Are They?

Canada’s D-Wave claims it has already built quantum computers, but scientists have questioned this claim. Tomaso Calarco, director of Integrated Quantum Science and Technology, said the scientific community has not recognized D-Wave’s machines, according to Newsweek.

Nevertheless, Ilyas Khan, co-founder of Cambridge Quantum Computing, said quantum technologies will be of practical importance in a short time.

Also read: NSA is working on an encryption-cracking quantum computer

What Can Be Done?

To protect bitcoin from quantum computers, new cryptography standards must be incorporated into the bitcoin protocol. Such technologies exist already. Llew Claasen, executive director of the Bitcoin Foundation, said many cryptographers already are working on a solution to phase in quantum-proof technologies to the bitcoin network.

The question will be in deploying them.

Bitcoin is doomed, according to Tomlinson. Any disruption that requires the bitcoin community’s consensus, something that can’t even be accomplished with the cryptocurrency’s transaction limit problem. The transaction limit problem is simple compared to reworking the complete digital signature method, Tomlinson said.

Quantum processor prototype image from iStock.