Bitcoin Forum

In 10 years from now a quantum computer will have sufficient computation power to give a 51% attack on the bitcoin network.

Please discuss.

Now that's the kind of system I want to play Halo on.   

Well, technical progress does not stand still and this is quite normal. Specialists have a full ten years to solve this problem. Undoubtedly, there will always be a way out, but from such power of quantum computers there will also be a benefit: it will be possible to recover lost keys from bitcoins and other cryptocurrencies.

Quantum computing has been discussed to death on this forum and each discussion is the same. The Bitcoin encryption can be "upgraded" to make it even impossible for quantum computers to find the Private key, so this is a non-issue. Yes, people who would not be able to transfer their coins to the new "upgraded" addresses, might suffer some losses, but the others will be safe.

There will be advance warnings before this happens <Because most Bank and financial networks use similar encryption> and the developers already worked on solutions for this kind of scenario.  ;)

In 10 years Bitcoin+blockchain:
1.Won't exist.
2.Will improve to a level,in which quantum computers won't be a threat,they could even help. ;D
Let's hope that the second option will happen.
This topic has been discussed 100 times before,so it's pointless to ask the same questions again and again.

no, you first discuss why you think in 10 years a system (quantum computer) that is not capable of producing hashrate and is not even designed for that is going to be able to suddenly produce such an unbelievably huge hashing power that could attack bitcoin!

So you think quantum technology power will increase but crypto and it's security level will be same.you might rght if only we are talking about bitcoin only

Lol!! Quantum computing is still under development and we don't yet have a realistic timeline! What we all are doing is speculation. Intel has just created a superconducting chip for such computing  and it is still being tested. If quantum computer becomes a reality, will probably cost few millions and the usage will be restricted for governmental and research related use.

Hackers won't have access to it just to launch 51% attack of crypto networks! Chill and take out such ideas from your mind!

Can you thought for at least a moment, if a quantum computer attack BTC, a same kind of quantum computer can be at BTC side, protecting?
There are 2 sides always, people "forget" to mention that the code of BTC will evolve and there's a huge community interested in protecting BTC

We already have a number of projects regarding quantum safety measures like Vault Chain.

There will always be a defence in the way. Blockchain technology is developing day by day so even quantum computer won't be able to attack Bitcoin.

Quantum computing is under development, and the same won't disturb the bitcoin network in ten years of time. During its early days into existence bitcoin network was possible to be run on a person computer, as the days passed the computational power required keeps increasing. After ten years time the development of the network will be high, and to the same the quantum computing will not make any big impact on the network.

1. Bitcoin and Blockchain are immortal, so they both will exist buddy even if no one uses them, which they 100% will use at least blockchain and I am pretty sure 10 years is to soon to ditch bitcoin, but it will be ditched at some point when people realize a fair distributed supply is how you make a money supply that is not a ponzi scheme, all other coins will become niche.

2. Quantum computers or a pool of lesser computers will always be a threat with the current system, Hopefully they change the consensus algorithm so instead of 51% of the hash power, it is 51% of the users. (spoiler: it is not going to happen with bitcoin unless satoshi comes back, pretty sure the person is dead)

Is it a general agreement of a consensus of people if 10 people out of 1000 agree on something because they have more money or hashing power?

con·sen·sus
    a general agreement.

gen·er·al
    affecting or concerning all people.

Unlikely, given that quantum computing are unlikely to offer any advantage in attacking SHA256:


Granted, running the hashing algorithm and searching for collisions are two very different things, but it goes to show that quantum computing is not some kind of magic all-seeing oracle for which the laws of mathematics don't apply.

Additionally modern Bitcoin mining is done via ASICs which offer even more of an advantage over regular CPUs that are usually the benchmark for comparing classical to quantum computing.

Also keep in mind that even if quantum computers where more efficient than ASICs at mining Bitcoins they would more likely be used to simply mine Bitcoin rather than attacking the network.

Why don't we think that after 10 years the Bitcoin technology will ensure its own safety, I think that's feasible when blockchain technology can be upgraded and improved, providing superior certainty.

Check out the past discussions as there were many topics regarding quantum computing in the past and i have shed my opinions in the past, the amount of money you have to spent in order to make any meaning attack is the first hindrance and no one in the right sense will spend billions to destroy something even for experiment case and the realistic possibility is none as companies have spent more money to built a quantum computer for decades now and none of them are really successful till now.

But in the next 10 years, bitcoin networks will increase network security. So quantum computers will not be able to attack their networks. You forget that when computer technology develops, on the other hand there are many technologies that are also developing, so you cannot say that the quantum computer itself developed at that time.

Maybe earlier:

Why would they want to attack the Bitcoin network with a quantum computer when they can mine blocks using it, but again I guess mining with a quantum computer would still not be enough, but with so much power on your CPU device I guess you can sure do a ton of gaming with it, Well in my opinion I will not gonna use it in gaining bitcoin and destroy the bitcoin ecosystem, That much worst depreciating the price of bitcoin now that it is in the bull run state, But for cryptocurrency sake I guess Quantum Powered Miner will be created in mining blocks for every cryptocurrency and Bitcoin can be possible.

You can't mine with a quantum computer.

You can only generate the privatekeys. That is what some groups will try: bringing back the lost coins or 'shalecoins' to the blockchain as active coins. https://bitcointalk.org/index.php?topic=5134441.0

Why it will be so? How do you know?

Quantum computers are computers which exploit quantum mechanics to do certain computations far more quickly than traditional computers. https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin
generating the privatekey: yes
hashing the next block: no

They will try it, because it is possible. Their reward will be huge.

People do really love to go ahead of time which ive been seeing these several topics and discussion about quantum computer.We might reach those era but it would really
be still so soon to see this upgrade.It can possible affect crypto yet we know on how quantum computing does but pretty sure there would be such changes later on.
Its impossible for cryptospace not to be quantum immune one.

No, albeit Bitcoin can be improved to be even more resistant, it is of my knowledge that Bitcoin right now is safe, IF people stick to using Bitcoin addresses ONCE, and only ONCE.

Once the proposed soft fork or whatever gets passed, then even this won't be as critical, but as it has always been since the beginning, if you want to be safe, use your Bitcoin address only once, then move on to the next one.

This is unrelated to the 51% attack, that doesn't even need to break the encryption, or use quantum computing.

Deriving the private key of old addresses that got reused and still have balance: eventually.

Deriving the private key of old address with no outgoing transactions: no.

The majority of "lost" coins fall in the latter category. Quantum computing can't bring back old coins just like it can't bring back your grandmother.

Are you from the future? Where do you got this estimate from , form fox news or some fake news page?
Because this is just fake. Quantum computing is far from being a reality even in 20 year time.

Yes,some separate advancements has been made but full computing device is something completely different.

Professor O’Brien: "In less than ten years quantum computers will begin to outperform everyday computers"
“The very fast computing power given by quantum computers has the potential to disrupt traditional businesses and challenge our cyber-security. Businesses need to be ready for a quantum future because it’s coming.”
Quantum computing is coming – are you prepared for it?
http://www.bris.ac.uk/physics/news/2016/quantum-computing.html

Quantum computers are expected to exceed the capabilities of classical computers in the next five to 10 years and promise vast increases in processing power over silicon chips.
https://thenextweb.com/future-of-finance/2019/07/15/quantum-key-distribution-to-secure-bank-account/

Some of Britain’s most distinguished computer scientists have moved to Silicon Valley to produce a quantum computer that can be sold commercially within five years.
https://www.thetimes.co.uk/article/quantum-computing-lures-scientists-to-us-g7kkkkvjw

Accessible quantum computing is just around the corner
https://techhq.com/2019/07/accessible-quantum-computing-is-just-around-the-corner/



Maybe earlier:

Stewart Allen, COO of quantum computing startup IonQ:
“I think in two or three years we’ll have businesses that are using quantum to solve real-world problems,” explained Allen; in the coming years, we can expect to see a trend of early adopters who want to have a “first-mover advantage”.
https://techhq.com/2019/07/accessible-quantum-computing-is-just-around-the-corner/

'Shalecoins' will be moved and are their (the first group) reward. That is the big Bitcoin challenge.

Then we will have a quantum secure network.

As others have mentioned this topic has been discussed and debated in this community many times already. To the OP, I would suggest to read this thread: I don't believe Quantum Computing will ever threaten Bitcoin (https://bitcointalk.org/index.php?topic=5157696.0).

Lots of "qualified" experts there sharing their opinions and thoughts about the subject matter, I will also urge others to really read that whole thread  to fully understand everything, just saying.

Well the fear is quantum computers can crack classic crypto, but there is a catch: There will be quantum crypto, so things go back to the same again. There is a transitional moment where a select few would have the massive early quantum computers (remember the old computers) but as with everything, technology gets mass produced and cheaper and will find its way to everyone's hand, and at that point quantum crypto will be common.

In the meantime there ARE quantum resistant crypto algorithms, and one of those is proposed for soft-forking Bitcoin way before this ever becomes an issue.

More than "replacing" i think quantum will become an add on, i think at some point there will be quantum co-processors available. There are things general computing can do better than quantum, and vice-versa. I imagine a century later the same cpu will have both things integrated.

Right now a 7qubit computer is several stories tall so, no, not quite there yet :)

But there are reported experiments with around 50qubits, a general quantum computer is yet to be built (publicly). I can imagine the NSA will build and operate one secretly so they can spy everyone's encrypted communications for a while until the technology reaches the masses. So its back to a 60ies style era where the State (and others) can and will spy on you until computers got good and small enough for common people to use cryptography.

The rate of our evolution will probably keep increasing with technological advancements like Quantum computers, cold fusion plants, Artificial Intelligence and Robotics.

I am just sad that I'll probably won't have enough time to enjoy a future of humanity uniting and prospering, with space exploration becoming our main target.

So there is not much point in discussing Bitcoin along with Quantum computers. I was about to type that I doubt it will be still relevant, but I'm afraid that after 10 years someone will reply to this post about how dumb I was  :-X :-X :-X :-X

A quantum computer, a calculating machine that utilizes quantum physics in the calculation process. This machine is predicted to have capabilities that far exceed the computers we use today. Computers that we often use now provide so many benefits that our parents might not be able to imagine. We can use this "classic" computer for simple things like calculating the price of groceries, making school assignments, communicating through social media, and discussing our faces and voices through the artificial intelligence they have. The unimaginable benefits will be realized in the future by the realization of quantum computers. With quantum computers, it is hoped that super-complicated calculations will require very large numbers to be done. Pharmacologists can count every atom in a drug that can fight viruses quickly and accurately to produce drugs that are more effective against disease. You might not use a quantum computer to update the status of social media, because that means the function of a quantum computer will be redundant. But, pharmacologists, physicists, chemists, and computer scientists will be greatly helped by the existence of quantum computers. More innovations that will benefit humanity will be generated from their calculations using quantum computers.

You forgot Satoshi's 1000000 bitcoins that have newer been moved, but still have their public keys visible.

Those addresses are difficult to protect from QC, because even if we implement a QC-resistant algorithm, those can't be protected or otherwise even Satoshi couldn't move them.

That's quite interesting, I didn't know that. I couldn't find anything useful on Google, got any more info on that? How are the public keys to Satoshi's old stash known, where public keys public before the protocol was changed to the way it works now?

At the beginning bitcoin used pay to public key (P2PK) instead of the pay to public key hash (P2PKH) that we are using now.
When using P2PK the public key is published in the blockchain when the "address" receives coins.

Actually. without QC, the P2PK  is even safer than P2PKH, because there is only ONE valid private key that can be used to spend coins from P2PK, while there are 2^96=79228162514264337593543950336 valid private keys to all P2PKH addresses. Because of the Ripemod160 hash.

I do not know any wallet that would still support paying to P2PK "addresses", but there are some scripts in the net that can still be used for creating  P2PK "addresses"

If a quantum computer is to appear in 10 years, then certainly Bitcoin will also be upgraded to be able to counteract that effect.  I wonder if quantum computers really threaten the existence of Bitcoin.  It has never happened and I think quantum computers will help exploit many times faster, the Bitcoin network will be stronger.

Do you even understand what quantum computing is and why we don't already have it? Quantum computing components need very energy intensive environments to even exist. I can give you an entire class on Q-bits and sub zero containment but all that would seem like a moot thing to do who thinks quantum computers would be invented to play games and mine or attack Bitcoins... that is so trivial.

Actually once you soft fork to add the quantum resistant code, you might also add something to keep those coins locked forever. Something along the lines of: By the date the new code activates, coins not moved to a new wallet that supports it become locked. You can wait a year or four (next halving), etc. to give people plenty of time... Well we will see what core brings regarding this matter.

If you keep those coins locked or something else what changes the original supply, you will create another sh**coin fork.

The original chain will always remain the main chain with all the mined coins. Bitcoin is a challenge network. There will be a quantum update. But whoever moves the coins with no owner from the old to the new addresses will be the new owners. That is what original Bitcoin is. That makes the community improve the network.


SHA-256 is not a quantum issue but to have an example:



Thereafter we would have two chains. The original chain and a forked one. To avoid such situations the Bitcoin community has to have an updated network all the time. That is the challenge.

The quantum update will mark the new beginning of Bitcoin as the lost coins will be active again.

It seems to me that lately humanity has already been at the peak of its mental abilities.  Even if a good result in the field of quantum technologies is achieved and a quantum computer is created, then in the coming decades this technology will be practically absent for a wider start, because it is still a very expensive thing.

And I don't think it will be this fast. When there were first Moon landings people were saying that a colonization of the Moon is just a few years ahead of us and then we will launch missions to other planets of the Solar System. We are decades later and there are no Moon bases or manned missions to Mars.

Many years will pass between the first prototype and a fully functioning quantum computer.

we've had these discussions before and the consensus (i think) is that it's not ethical to steal/lock satoshi's coins. bitcoin users never opted into a rule system where their outputs would be forcibly locked after a certain time. i understand the motives to do it but a fork like that would definitely split the network. it's too politically contentious. it would be a different story if the protocol were designed that way from the start.

i'm sure we'll eventually fork to a quantum resistant signature scheme but the fork won't do anything to stop vulnerable coins from being spent. those coins will eventually be stolen over time.

It is a problem if we have quantum computers now, but no, it is still that early that we don't need to think about it by now.

I don't think developers will just let destroy Bitcoin like that, obviously, they will be ready when the quantum computers are already up. I mean I agree with some of the posts here to use and play with it because damn! Ready Players One will not be a sci-fi movie or a dream anymore.

Why there are suggestions that a quantum computer will be able to destroy the cryptocurrency?  What are the prerequisites for this?  In my opinion, if computer technology changes, then cryptocurrency technologies will also be improved.

Write that quantum computers will be able to crack any digital codes in a very short time, including picking up the keys to our wallets for cryptocurrency. Therefore, it would be more correct to point out that quantum computers will not destroy a cryptocurrency, but will make it defenseless. Of course, it remains to hope for the emergence of new technologies of protection or fundamental changes in the secret keys from the wallets of our cryptocurrency.

We will have a quantum secure network. That is not an issue, but the 'shalecoins', coins with no owner, will become active. https://bitcointalk.org/index.php?topic=5134441.0

And that will be the most challenging thing. https://bitcointalk.org/index.php?topic=5166180.0

The Q System One is a beautiful piece of engineering, but the quantum computing future is still a way off (by IBM

So i guess those will belong to those willing to invest in quantum computing, which is still so far much more expensive than any potential gains...

Mine-able yes, profitable no. There will always be a group of hobbyists willing to mine for fun, or with "free" (renewable?) energy available to do so. Also the asics are getting even more efficient, so Cannan's idea of embedding a few asic chips in common household appliances will return. Yeah, your smart fridge/ac/router/tv/heater/whatever might have 1~10 THs, why not?

Its like getting one of those usb mining sticks and plug it permanently into your "smart" tv, just because you want to help the community and it doesn't make you go bankrupt anyway.

I know i will probably get into that group, with a node as well, because its one way i can help and thank Bitcoin, for letting me eat today, when the politicians and institutions stole our wealth and nobody else cared.