There are often talks revolving around the quantum computing revolution and its advantages to the computing world. However, there is also a downside to quantum computers. Quantum computers pose a threat to cryptocurrencies, and they could introduce changes that the cryptocurrency owners will not like.

A Real Threat

Quantum computers, with their unique property of quantum entanglement of particles, are very secure modes of information and it would be impossible to break it. It uses something called as a quantum key distribution (QKD) that helps them to keep the security intact.

Cryptocurrency work involves a private key that is used to access Blockchain and Bitcoin contained on it. Each transaction has its own cryptographic hash. The currency owner will generate two numbers, one of which acts like a ‘private key’ and the other one as a ‘public key’. The public key can be easily generated from the private key but the opposite cannot be done. There is a signature used that uses a technique called elliptic curve signature scheme, for the receiver to ensure that the owner is the one that has the private key. These two things give cryptocurrencies the security that it has, which is impossible to break with the current traditional computers, since the only way to get hold of the private key is calculating it using the public key.

Google’s quantum computing expert, John Martinis, is of the opinion that that even if his group could build a quantum computer in 10 years time, it would likely take a lot longer than that to break RSA. A quantum computer, due to Shor’s algorithm, could easily break the RSA encryption which is to secure data transmission on the Internet.

Quantum computers may have the potential to reduce times of brute force attacks by providing the network with exponentially larger amounts of processing power, as opposed to the computers today, for whom the brute force attack would likely take multiple lifetimes to pose any relative threat to the network.

A study by Divesh Aggarwal at the National University of Singapore with his research team had studied the threat of quantum computers to Bitcoin. According to their paper, they found that the proof-of-work used by Bitcoin is relatively resistant to substantial speedup by quantum computers in the next 10 years, mainly because specialised ASIC miners are extremely fast

compared to the estimated clock speed of quantum computers. It said, “The elliptic curve signature scheme used by Bitcoin is much more at risk, and could be completely broken by a quantum computer as early as 2027.” This research team from Singapore, Australia and France, in their paper, put forward that quantum computers could run fast enough to crack the cryptography on the network to steal cryptocurrencies.

Tackling The Threat

It is also pointed out that quantum computers do not pose any serious threat to the cryptocurrency security. Although quantum computer threat to the cryptocurrency is real, some experts believe that this quantum threat issue can be fixed. Jeffrey Tucker, Editorial Director at the American Institute of Economic Research, is one of the people with such an opinion. In his blog, he conveys that the fear of quantum computing as an existential threat to Bitcoin is based on scare-mongering and ignorance.

This plot above, taken from their paper, shows two estimates of the hashing power, in hashes per second, which is a mathematical function that turns data into a specific number of random string numbers, of the Bitcoin network in blue striped curves versus a single quantum computer in red striped curves, as a function of time for the next 25 years. the black dotted line shows the hash rate of a single ASIC device today.

Scientists from Victoria University of Wellington in New Zealand had done a research in which they proposed making blockchain behave like a quantum networked time machine to keep it safe. They showed that entanglement in time, as opposed to entanglement in space, provides the crucial quantum benefit.

HCash, a startup of Australia is also creating solutions for protecting against quantum hacking and its researchers aren’t the only ones racing to ensure this sort of thing can’t happen. HCash CEO Dallas Brooks has said, “The great thing about HCash is that it’s preparing for the inevitable.”

It is quite evident that we are already gearing up for the threat of quantum computing to cryptocurrency, even before the advent of the quantum computers.