Possibility of Quantum Computing significantly speeding up transactions per second (TPS) / transaction rate for blockchain consensus algorithm?

For example, Shor Algorithm, the most complex quantum algorithm known to date, has ‘exponential’ speed-up over classical algorithms.

Can distributed consensus algorithms of today be speed up to scale blockchain transaction rate to an unprecendented speed?

Nathan Aw

  • Quantum computing breaks ECDSA so it does not bode well at all for current distributed ledger technologies :)
    – Niklas B.
    Jul 13, 2019 at 14:27

3 Answers 3


There's a lot of things that could be sped up with quantum computing however it's not feasible with the current technology to do a lot of these things, I imagine transaction processing would be one of the things that would greatly benefit from quantum computing when the technology is more mature


Ethereum is not slow (tps) because it has to make difficult computations. Ethereum is slow because it needs to be fair to all participants considering the following issues:

1) latency. All data needs to be distributed to all nodes

2) coherency. All participants need to agree on the data and it's ordering (consensus)

3) distributed nature. No centralized authority doing the heavy lifting.

Essentially the slowness is due to the consensus protocol.

At this point I assume you are familiar with the basic concepts of mining.

If one node gained an unfair advantage in the mining (quantum computing?) the network would become less decentralized as the one node would complete more and more of the mining. But that would not increase the speed in any way. It only means that the one node solves the mining puzzle faster than other nodes and gets more rewards.

I can't think of a way how faster computing could make the network any faster - or slower. There is no difficult computing to be made except the mining part which is difficult on purpose.

A different consensus mechanism could change the speed but would also mean a radically different network. I'm not fully up to speed with the different consensus mechanisms but they all have their pros and cons - there is a reason Ethereum chose a "slow" mechanism.


The overall latency of the network is due to ALL the nodes involved in the consensus mechanism. If you look at the Quantum computer like a sort of supercomputer extremely fast, it is not so interesting to have some nodes super fast if you have some other nodes normally fast... so the index may be the totality of nodes or, in other word, the worst condition on the net prevails.

The true problem is if, having a quantum computer, the Ethereum network can survive. The node having the quantum computer can calculate, almost istantly, any private key and any other cripted data on the network and can, theoretically, solve all the network calculations in a very fast way.

Who can then trust the network? Difficult to answer!!!

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