Tech giants including IBM, Google, Intel, Microsoft, and Lockheed-Martin, are spending billions to develop practical quantum computing technology. Future quantum computers are expected to permit staying on Moore’s Law, the exponential acceleration of computing performance, first noticed by Intel founder Gordon Moore in 1965, which seems threatened by a slow-down in the progress of electronic miniaturization technology.

Quantum computers encode information in “qubits” that, instead of being in definite zero or one states like classical bits, can be in weird quantum superpositions of zero and one states, and process information in ways that have no equivalent in classical computing by exploiting subtle quantum phenomena.

Future quantum computers are expected to open the door to spectacular advances in very complex computational problems such as calculating the properties of promising new materials, large-scale financial analysis, molecular simulations for more effective drug development, and Big Data analysis for homeland security applications, much faster than today’s fastest supercomputers.

It’s important to emphasize that “much faster” doesn’t mean 20 percent faster, or twice as fast. The theoretical performance leap forward that quantum computers could achieve is nothing short of breathtaking – quantum computers could solve certain computational problems millions of times faster than conventional computers.

Of course there are practical challenges to solve, for example the quantum processes on which quantum computing depends are extremely vulnerable to environmental noise, but that’s why the tech giants are spending billions. It seems likely that, if they throw enough money at the problem, practical quantum computers could be developed in one decade or so.

Code-breaking applications are considered as especially suitable for quantum computing, which raises the spectrum of future hackers (perhaps backed by government agencies) equipped with ultra-fast quantum computers breaking the “primitive” encryption technology used in Bitcoin and other crypto-currencies, cracking private keys, and taking all the money.

“[Current] blockchain platforms rely on digital signatures, which are vulnerable to attacks by means of quantum computers,” reads a new research paper titled “Quantum-secured blockchain,” authored by team of researchers from the Russian Quantum Center (RQC) and associated research centers.

In the paper, the researchers describe an experimental realization of a quantum-safe blockchain platform that utilizes quantum key distribution across an urban fiber network for information-theoretically secure authentication.

Quantum Key Distribution (QKD) permits securely sharing keys for one-time pad (OTP) cryptography. OTP encryption is mathematically guaranteed to be unbreakable, even by quantum computers, but only if the keys are not compromised. Therefore, secure key transmission and storage is the main challenge for ultra-secure OTP cryptography. QKD, which permits establishing a shared key in such a way as to permit detecting any attempt to eavesdrop on the key, offers invulnerable security based on the laws of fundamental physics.

“[We] have developed a blockchain protocol with information-theoretically secure authentication based on a network in which each pair of nodes is connected by a QKD link,” note the researchers. “We have experimentally tested our protocol by means of a three-party urban fibre network QKD in Moscow.”

A press release issued by the RQC notes that the quantum blockchain prototype was tested on a heterogeneous network of quantum communications created by the RQC on the Gazprombank platform. Gazprombank is one of Russia’s largest banks.

“In our quantum-secure blockchain setup, we get rid of digital signatures altogether. Instead, we utilise quantum cryptography for authentication,” research team leader Alexander Lvovsky told IBTimes UK. “Parties that communicate via a quantum channel can be completely sure that they are talking to each other, not anybody else. This is the main idea. Then we had to re-invent the entire blockchain architecture to ‘fit’ our new authentication technology, thereby making this architecture immune to quantum computer attacks.”

Picture from D-Wave/Wikimedia Commons.