A whitepaper has been released which finds that Bitcoin and other crypto currencies will be vulnerable to attacks by quantum computers in as little as 10 years. The paper describes such attacks could have a disastrous effect on crypto currencies, a market now worth over USD $150 billion as hackers equipped with quantum computers could easily steal the funds without detection. They also assess the risk of quantum dominated mining in so called Proof of Work protocols which are the basis for verifying transactions in Crypto currency and Bit coins.
Quantum computing uses quantum bits that can exist in any superposition of values between 0 and 1 thus creating large information which is the limit of classical computing systems. The capacity to compute using quantum bits renders quantum computers many orders of magnitude faster than classical computers. Google shared a D-Wave quantum annealing computer could be 100 million times faster than classical computers at certain tasks. And Google and IBM are working on their own quantum computers. Hence, a working quantum computer could, in theory, break today’s public key cryptography.
Quantum computers capable of speedy number factoring are not available yet. If quantum computing continues emerging, it will get there eventually. This advance will pose an existential threat to public key cryptography, and the blockchain technology that relies on it, including Bitcoin, will be vulnerable to hacking.
"Understandably, there is a lot of nervousness in cryptocurrency communities about whether their digital assets will resist future attacks by very fast quantum computers. Our service is providing advice and algorithmic protocols to digital currencies and blockchains like Hcash who want to certify their product will be quantum safe. HCash has put emphasis on quantum security from the start so this collaboration will be a benefit to both teams" says co-author Brennen, who is director of the Macquarie Quantum Science and Technology Centre (QSciTech) where researchers work on quantum science theory and experiment.
However, quantum computing is a threat for all computer security systems that rely on public key cryptography, not just blockchain. All security systems, need to consider post-quantum cryptography to maintain data security for their systems. But the easiest and most efficient route may be to replace traditional systems with blockchain systems that implement quantum-resistant cryptography.