Scientists Propose Blockchain's Quantum Proof-of-Work Consensus

Author: TRISTAN GREENE, Cointelegraph; Compiler: Songxue, Jinse Finance

A team of researchers from universities in Australia and the United States, in collaboration with quantum technology company BTQ, recently published research proposing a new proof-of-work (PoW) scheme for blockchain consensus that relies on quantum computing technology to verify the consensus.

The preprint research paper, titled "Achieving Proof-of-Work Consensus via Quantum Sampling," details a system that the authors claim** has "significant speedups over computation on classical hardware and is more energy efficient." **

According to the researchers, current algorithms for solving the PoW consensus puzzle are slow and require massive computing resources to process:** "While classic PoW schemes like Bitcoin are notoriously energy inefficient, our Boson-sampling PoW schemes enable a more energy-efficient alternative to quantum hardware implementations."**

According to the paper, the quantum advantage provided by the scheme will also increase the difficulty of mining, so as the number of miners increases, it becomes possible to "maintain consistent block mining time", which can further incentivize the continuous participation of "quantum miners".

The sampling process the researchers refer to, boson sampling, is not an entirely new idea, but its application to blockchain technology appears to be innovative. Boson sampling has shown promise in numerous quantum computing applications. Still, as a non-universal quantum computing solution (it must be used in systems built for specific tasks), its potential is limited to a few fields, such as chemistry.

However, according to the researchers, it could be the perfect solution for future-proof blockchain applications and has the potential to reduce the environmental impact of mining on the bitcoin blockchain and similar blockchains.

In addition to the quantum advantage, quantum hardware also has an advantage over older computers due to the nature of blockchain mining work.

One of the current advantages of classical supercomputers over newer types of quantum computers is the ability to perform "precomputation" when working on the same type of problem on a regular basis. However, when it comes to blockchains, this precomputation is basically wasted.

Mining is, as the researchers put it, a "no progress" problem. No matter how many times blockchain puzzles are solved to provide proof of work, the challenges posed by computers and algorithmic processing can never be better.

**This means that, although quantum computers are challenging to develop and expensive to build and maintain, they will eventually be able to verify consensus more efficiently than state-of-the-art classical systems. **