D-Wave Quantum Inc. has released a new research paper outlining a novel blockchain architecture that integrates quantum capabilities with traditional blockchain technology to enhance security and increase efficiency.

In the paper, “Blockchain with Proof of Quantum Work,” introduced Thursday, D-Wave built and tested a “proof of quantum work” algorithm that uses quantum computation to generate and validate blockchain hashes.

“This is the first time a blockchain has successfully operated on a distributed network of four quantum computers across two countries,” said D-Wave Chief Scientist Dr. Mohammad Amin.

Blockchain technology is a decentralized, digital ledger that distributes transactions across multiple databases grouped into “blocks” linked into a “chain,” making it difficult to tamper with. Each block is secured by a cryptographic hash linked to the previous block, meaning changing one block requires changing all blocks it’s linked to. Since blockchains are distributed across multiple nodes in a network, each transaction and block must be validated before it can be added to the chain.

To validate transactions, bitcoin, the leading cryptocurrency with a market capitalization of around $1.67 trillion, employs “proof of work.” In this consensus mechanism, miners across the network compete to solve intricate cryptographic puzzles, generating hashes that determine the next block added to the blockchain.

The complexity of the algorithms needed to compute proof of work is so high that significant amounts of energy are used to complete the validation of bitcoin block mining. It is estimated that the power consumption for the bitcoin blockchain is around 175 terawatt-hours annually, which is comparable to Poland’s.

D-Wave replaced the traditional proof of work algorithms with proof of quantum work techniques using multiple quantum-based hash generation methods and tested varying levels of complexity. The company also developed a methodology to handle the inherent probabilistic nature of quantum computing to maintain stable blockchain validation.

“Despite spanning two generations of D-Wave annealing quantum computers with different architectures and fabrication stacks, the systems’ outputs were able to cross-validate each other and facilitate stable blockchain operation for thousands of transaction blocks,” Amin said. “We believe that this approach could significantly reduce energy consumption and enhance security.”

Electricity costs are estimated to comprise 90% to 95% of blockchain mining expenses. D-Wave’s researchers said that in its proof of quantum research, energy consumption amounted to “a small fraction of quantum computation cost on D-Wave quantum computers.” They added that switching from PoW to PoQ could reduce energy consumption by a factor of 1,000.

This news comes shortly after D-Wave announced it achieved the milestone of “quantum supremacy,” although some academics in quantum computing have questioned the company’s findings. Quantum supremacy is the point where quantum computers can finally solve problems considered impossible for even the most powerful “classical” computers.

According to the researchers, classical computers cannot predict the outcomes of the quantum hashing processes used in PoQ, making quantum computers more secure for calculating the cryptographic hash values for blockchain blocks. This inherent unpredictability would aid against potential traditional cryptographic attacks and thus enhance overall security.

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