Quantum is key to securing blockchain, say researchers

June 1, 2018, ResearchSEA
Credit: CC0 Public Domain

Although blockchain is traditionally seen as secure, it is vulnerable to attack from quantum computers.

Now, a team of Russian researchers has developed a solution to the -era blockchain challenge, using (QKD).

Writing in the journal Quantum Science and Technology, the researchers set out a quantum-safe blockchain platform that uses QKD to achieve secure authentication.

The blockchain is a distributed ledger platform that allows consensus in a large decentralized network of parties who do not trust each other. Transactions are accountable and transparent, making it useful for a variety of applications from smart contracts and finance, to manufacturing and healthcare. One of the most prominent applications of blockchains is cryptocurrencies, such as Bitcoin.

Lead author Dr. Evgeniy Kiktenko, from the Russian Quantum Center, Moscow, said: "Blockchain is promising for a wide range of applications. But current platforms rely on , which are vulnerable to attacks by quantum computers. This also applies to the cryptographic hash functions used in preparing new blocks, meaning those with access to quantum computation would have an unfair advantage in procuring mining rewards, such as Bitcoins. These risks are significant – it is predicted that 10 percent of global GDP will be stored on blockchains or blockchain-related technology by 2025.

To overcome these risks, the researchers developed a blockchain platform combining original state-machine replication – a general method for implementing a fault-tolerant service by replicating servers and coordinating client interactions with server replicas – without use of digital signatures, and QKD for providing authentication

They then ran an experiment to test its capability in an urban QKD network.

Co-lead author Dr. Aleksey Fedorov, from the Russian Quantum Center, said: "Using QKD for blockchains may appear counterintuitive, as QKD networks rely on trust among nodes, whereas many blockchains lack such trust. More specifically, one may argue that QKD cannot be used for authentication because it requires an authenticated classical channel for operation itself.

"However, each QKD communication session generates a large amount of shared secret data, part of which can be used for authentication in subsequent sessions. Therefore, a small amount of 'seed' secret key that the parties share before their first QKD session ensures their secure authentication for all future communication. This means QKD can be used in lieu of classical digital signatures."

In addition to using QKD for authentication, the researchers redefined the protocol of adding new blocks in a different way from modern cryptocurrencies. Rather than concentrating the development of new blocks in the hands of individual miners, they employed the information-theoretically secure broadcast protocol, where all nodes reach an agreement about a new block on equal terms.

Co-lead author Prof. Alexander Lvovsky said: "A crucial advantage of our blockchain protocol is its ability to maintain transparency and integrity of transactions against attacks with quantum algorithms. Our results therefore open up possibilities for realising scalable quantum-safe blockchain platforms. If realised, such a platform can limit economic and social risks from imminent breakthroughs in quantum computation technology."

Explore further: Using a quantum blockchain to protect blockchains of the future

More information: E O Kiktenko et al. Quantum-secured blockchain, Quantum Science and Technology (2018). DOI: 10.1088/2058-9565/aabc6b

Related Stories

HSBC, ING banks announce blockchain first

May 14, 2018

Banking giants HSBC and ING on Monday said they had carried out a landmark blockchain transaction aimed at speeding up payment processes and making them more secure.

Towards sustainable blockchains

May 4, 2018

As blockchains become ever more popular and widespread, a growing concern is their sustainability. Current designs, most notably the blockchain underlying the Bitcoin cryptocurrency, are secured using so-called "proofs of ...

France to allow trading of securities via blockchain

December 8, 2017

France's finance minister unveiled Friday a decree that would make it the first nation in Europe to allow the trading of some non-listed securities using the blockchain technology that underpins cryptocurrencies.

Recommended for you

Scientists produce 3-D chemical maps of single bacteria

November 16, 2018

Scientists at the National Synchrotron Light Source II (NSLS-II)—a U.S. Department of Energy (DOE) Office of Science User Facility at DOE's Brookhaven National Laboratory—have used ultrabright x-rays to image single bacteria ...

Bursting bubbles launch bacteria from water to air

November 15, 2018

Wherever there's water, there's bound to be bubbles floating at the surface. From standing puddles, lakes, and streams, to swimming pools, hot tubs, public fountains, and toilets, bubbles are ubiquitous, indoors and out.

Terahertz laser pulses amplify optical phonons in solids

November 15, 2018

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg/Germany presents evidence of the amplification of optical phonons ...

Quantum science turns social

November 15, 2018

Researchers in a lab at Aarhus University have developed a versatile remote gaming interface that allowed external experts as well as hundreds of citizen scientists all over the world to optimize a quantum gas experiment ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Hyperfuzzy
not rated yet Jun 03, 2018
i would suspect my entire chain of programmers; thus, first, "Where is the human interface? i..e. unique hw, unique cloud, ... , then, communicate, face to face; medical instrumentation ..! What? The AI knows all before you communicate! Traffic?

Would it be easier if "IT" suggested human response to everyone to maintain a standard of living for those hooked up, fit the Plan, needed professions, molecular controls, bio-, etc.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.