Bitcoin Forum

With the steps forward that quantum computing is making will it mean the end of crypto as we know it once quantum computing become a reality?

I mean it effectivly makes encryption useless, someone with a quantum computer could just brute force a private key from a public key in no time. This will kill every crypto currently out there.

Do you think we will see new quantum cryptos released once the technology is ready? Or do you think Bitcoin will adopt a new layer of quantum security if that is even possible?

I'm by no means an expert on the subject but unless the good guys get their hands on some form of quantum computer before the bad guys it kind of puts a ticking timer on the whole crypto industry. That's if an extra layer of quantum encryption can even be implemented in some way for Bitcoin.

If not, then I guess we better time it just right and get the f**k outta here at the right time.

Thoughts?

It is not the way you put it. We have quantum resistant cryptographic algorithms out there, already:
https://en.wikipedia.org/wiki/Post-quantum_cryptography
I'm specially a fan of this one:
http://ieeexplore.ieee.org/document/6337933/?reload=true

Quantum computing is too immature to be considered a threat for at least this decade and when it happens to be ready, we are ways ready. Just don't panic. ;)

Great resource! Thanks for sharing that. So I take it that if post-quantum cryptography is already being worked on in order to be prepared then that extra layer of security can be written into the Bitcoin code, even that far down the road?

Panic over I guess  ;)

No. If quantum computing does become a reality, the time taken to bruteforce a private key to a public key will decrease substantially but not to that much magnitude.

Yes. https://media.giphy.com/media/Oz6jBpIGs8Ra/giphy.gif

---

I am not currently aware of any development on such an algorithm for now. With reference to my initial post, the security risk of this can be easily mitigated. As long as people do not reuse addresses, it is quite hard for anyone to profit using a quantum computer. Speaking of profits, the cost of operating one is quite expensive and not everyone can have their hands on it.

Bitcoin is inherently resistant to quantum computing as it does not disclose the public key, instead it hashes it twice! So the attacker literally has no chance to 'derive' the private key even armed to a super quantum computer like in a science fiction.

So far so good, BUT when one 'spends' his wallet, eventually has to disclose his/her public key and if s/he accidentally tries to use the same address again, well, from here on the alarming flags should be raised if there are powerful enough QCs commercially available.

Note:
In the limited interval between the time of the spend Tx even for the brand new addresses, until they get confirmed, there is a window for the QC attack to compromise the private key and generate another transaction with higher fee and priority and steal funds, taking advantage of this window needs very huge QCs to break the code very fast, not like few days, but few seconds. Such QCs not likely to be built ever.

Anyway, when it comes to upgrade, there will be a soft fork, implementing new address types and thus new cryptographic algorithms. After  the fork, all new transactions will be safe in heaven, the only weakness will be the elder UTXOs with used addresses, though it will be the holders' responsibility to renew their wallets asap.

:)

Ok I understand, I guess it's always hard to predict the capability of future technology but even so sounds like it wouldnt be an issue/is easily overcome.

Thanks for helping me clear that one up in my own head!

Of course, I didnt even think about the fact the public key is already hashed!

Glad to hear our Bitcoin will be safe from the world of science fiction.

I think a long Sunday afternoon must have taken it's toll, my imgination has been for a good wonder today...

Thanks for the info though!

Unfortunately, in the earlier stages of Bitcoin, P2PK was implemented instead of P2PKH. The earlier transactions, specifically those that were mined to were vulnerable with the default implementation using P2PK.

That includes the genesis block and many addresses with transactions around that time.

Those addresses with 50BTC can potentially be vulnerable.

Really, I wasnt aware of that. That would surely be profitable for someone if they could exploit that vulnerability in the early blocks. At least it wouldnt bring down Bitcoin as whole though....

Also, the moment you spend bitcoins from an address you reveal that address's public key. Not a problem, if you never reuse an address (which is how most wallets work now, creating new change addresses for each tx). Although if quantum computers are fast enough to break a private key in a few minutes to an hour, you could potentially take any tx from the mempool with a fat public key, reverse its private key, build a new tx spending the funds to your address and replace the old one with replace-by-fee.

It wont be soon, to decipher the secret key for an acceptable time, you need to have a computer with 100 million qubits, and now only a computer with 49 qubits is being developed.

It's going to take some time.

It is crazy just how many things scientists have considered "impossible", only for them to be achieved sometimes centuries earlier than predicted. One recent example is AlphaGO. With that said, I wouldn't put anything past the realm of possibility, but with the amount of money invested in Bitcoin globally it is unlikely that if this were to happen we wouldn't find a solution.

The main threat, as have been mentioned earlier in this topic, is an imaginary multi million qubit quantum computer being so powerful that can crack a disclosed public key while its container (a spend transaction) is stuck in the mempool (few minutes). It is mainly due to the fact  that this hypothetical crack wont compromise the wallet as a whole (we re-use our wallets).

HD wallets are de-facto standard and commonly used now and they secure the process in a way that  the attacker MUST complete its mission in the short time frame in which a transaction is publicly announced and not confirmed yet. The trick is that once the confirmation takes place, compromised public and private keys will become useless, the remaining balance has mowed to a fresh, although dependent, new public/private pair of keys which their master private key is well secured by the owner (hope so) and the master public key have not to be exposed ever.

For the fictional ultra-super quantum computer giant case, the solution is out there with quantum resistant cryptography, it is just about implementation and a soft fork for which we have a lot of time, say 1-2 centuries. It really takes that long with any measure to have multi million qubit quantum computers around.

Conspiracy theories have been proposed that NSA or CIA have access to much powerful QC tech than what is publicly disclosed, while it is disputable and controversial and one can ask that how far they can go, anyhow, in practice, they can't  use their hypothetical "super power" against bitcoin even once, because by doing this, they will disclose their access to such a technology and escalate competition and research for countermeasures.

Good thought. Personally I think blockchains will be the way to go, since banks will probably lag in the update to quantum resistant security measures. Communities like these are faster at adopting such technologies.

No, because quantum is still in early stage of development, and with quantum computing, also quantum cryptography will be developed.

it will not kill it, but crypto's will have to adapt to quantum computing.,

Glad to hear most people think that Bitcoin will survive. I suppose its a bit of a guessing game but for now at least we are on top of any potential changes

Quantum computing is still in its starting phase. It will still need couple of decades to become a threat to cryptocurrencies. I read it somewhere that at present quantum computing is focused upon only energy landscape issues and not on solving regular mathematical problems. We need a major revolution in our ability to build reliable qubit logic before we can even think about solving complex cryptography and that problem is nowhere near being solved at the moment.

Sure I get that but just look at where there internet has gone in the last 20 years. I'm sure if you went back in time 20 years today's reality would have been thought of as impossible. Technology moves at such a great rate that it would be hard to predict 5 years into the future let alone another 20.

I don't know why you say that.  Even in Satoshi's genesis block, the output script is

41 04 67 8A FD B0 FE 55 48 27 19 67 F1 A6 71 30 B7 10 5C D6 A8 28 E0 39 09 A6 79 62 E0 EA 1F 61
DE B6 49 F6 BC 3F 4C EF 38 C4 F3 55 04 E5 1E C1 12 DE 5C 38 4D F7 BA 0B 8D 57 8A 4C 70 2B 6B F1
1D 5F AC

that is essentially a bitcoin ADDRESS, meaning, it is a hash of a public key.

Probably not, honestly.

So, when quantum computing leaves its infancy, I'm pretty sure it'll be the catalyst that moves humanity closer to singularity. With actual quantum computing, we'll be able to effectively simulate the universe.

Ideally, Bitcoin and all currencies will be dead by this point and capitalism will have fallen entirely.

Against any poison always has an antidote. Quantum computers, it will not be soon. If you panic because you, we urgently need to curtail all space programs because someday it will built a spaceship with photon drive.

Wat.

" Do you think we will see new quantum cryptos released once the technology is ready? Or do you think Bitcoin will adopt a new layer of quantum security if that is even possible"


The bolded would likely be the case. Been following the Quantum stuff for years now, looks like it is year 2030 technology, by then developers will most likely figure out how to keep things from being hacked or we will never have Crypto and Blockchain anymore.

By the way IBM may have developed some basic quantum computers/technology. They have been on the Quantum thing for years

Bitcoin is inherently resistant to quantum computing as it does not disclose the public key, instead it hashes it twice! So the attacker literally has no chance to 'derive' the private key even armed to a super quantum computer like in a science fiction.

So far so good, BUT when one 'spends' his wallet, eventually has to disclose his/her public key and if s/he accidentally tries to use the same address again, well, from here on the alarming flags should be raised if there are powerful enough QCs commercially available.

Note:
In the limited interval between the time of the spend Tx even for the brand new addresses, until they get confirmed, there is a window for the QC attack to compromise the private key and generate another transaction with higher fee and priority and steal funds, taking advantage of this window needs very huge QCs to break the code very fast, not like few days, but few seconds. Such QCs not likely to be built ever.

Anyway, when it comes to upgrade, there will be a soft fork, implementing new address types and thus new cryptographic algorithms. After  the fork, all new transactions will be safe in heaven, the only weakness will be the elder UTXOs with used addresses, though it will be the holders' responsibility to renew their wallets asap

@Droplex

I understand you are new here but yet ....

Why do you just copy/pasted my post above? You can use Quote button on any post to just have it all copied in your reply and tagged properly, then you can add your comments like saying: "I strongly support this opinion"or "I don't get it" or .... Instead, you just copied my post's text simply, violating my copy left  :P

Bitcoin will remain safe regardless of how powerful quantum computers are. Bitcoin’s encryption protocol will likely remain safe. Bitcoin’s underlying encryption protocol, SHA-256, is stubbornly resistant to nefarious attempts to undermine it. It is likely strong enough to withstand assaults from even the most savage quantum computer onslaught.
Moreover, Quantum computers are not much capable of solving cryptography. They are not that powerful of solving difficult problems. Hence, Bitcoin is safe.

Some people are saying it will. It is actually quite scary. And imagine just how fast a quantum computer could mine Bitcoins... :o

It could either kill crypto, or provide a massive boost to it. Imagine how powerful the miners will be. It will be like back in 2009. lol!

Doesn't www.theqrl.com    The Quantum Ledger solve this problem and offer a store of value that is quantum resistant? Couldn't Bitcoin integrate elements of this project?

https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin

copy/paste from a trading thread I wrote in a couple days ago:

https://www.sciencenews.org/article/quantum-computers-are-about-get-real

TL;DR: 50 qubit quantum computer available commercially within a few years.
Small versions (5 qubits) available to public via web access already.
16 qubit version available to beta test now.

These are real quantum computers too - not just quantum annealing thingies like D-Wave sells.

To me the quantum technology world is developing so to is the cryptographic world. The truth is if quantum becomes a reality and meets cryptography at it's current stage then cryptography will be dumped for a period of time until it catches up... Well nothing is impossible but to think that a fiction will one day come to reality and beat an already existing system is some worth out of the box. But we should not also forget that the very technology of quantum computing can also be used to to enhance cryptography because there are many cryptographic algorithms out there that will function amazingly well on quantum systems.
So there is nothing to fear about because both systems are developing and quantum systems can be used to enhanced cryptography last but not the least, there are already majors out there that are designed to combat such a situation  ...
https://en.wikipedia.org/wiki/Post-quantum_cryptography

This isn't correct. It will make Public Key Encryption (as we know it today) useless, but it doesn't break encryption writlarge. Crypto will have to adapt, but it will...just a matter of time

Even if it is successful, it will not be used here. It should be applied to military and scientific fields first 8)

If one individual person could afford quantum computer he can do whatever he wants.

I am not very technical person and don't know much about computers but i think it is not very hard to raise computing power which is needed to solve something. Let's say you have to guess 4 digit password it is done in no time, but 8 digit password is much harder to guess with brute force.

If the technology changes and if you are keep with the age old technology then it is possible,that wont be the case with crypto currency because the people behind these projects are smart people and they will be changing things when there is an upgrade in technology.After all quantum computing is a thing of the future but progress is made every day in this field as i saw a post regarding measuring of electrons in the quantum dot is possible now and with all these developments it will take a long time to become reality but with these advancements we will improve  from the current standards.

Bitcoin is programmable code and the developers has worked on fail safe replacements for current algorithms, if processing power catch up with the encryption techniques. SHA-2: A family of two similar hash functions, with different block sizes, known as SHA-256 and SHA-512. They differ in the word size; SHA-256 uses 32-bit words where SHA-512 uses 64-bit words. There are also truncated versions of each standard, known as SHA-224, SHA-384, SHA-512/224 and SHA-512/256.

Currently the most vetted hashing algorithm providing most security is bcrypt. < not sure if it is suitable for Bitcoin > ^hmmmmmm^

Technology is always a matter of time. But only if you remove money as one precondition. So, with the assumption of unlimited financial means, all technology is possible. But yes, Bitcoin is not stagnant. It is its nature to respond and adapt. It is not invincible. It is always vulnerable. But Bitcoin is moving, just as tech is.

quantum computers are reality long time ago already:
http://www.pcworld.com/article/3194574/hardware/china-adds-a-quantum-computer-to-high-performance-computing-arsenal.html
chinese have added quantum computers to their research pool
the thing is that at the current state of things, hashes will not be decoded on the fly (unless Snowden is right and ANB have backdoors in every crypto algorythm)
even with the help of the quantum computers,so no,bitcoin is/will be safe for at least another decade

Funny you mention that the Chinese have developed quantum technology, I just came across this on Facebook from the financial times: https://www.facebook.com/financialtimes/posts/10155458818350750

Says China have successfully developed quantum communication. Will be deployed in August.

Maybe things move quicker than what people think

I want to advise an excellent equipment store for crypto currency asic-minerworld.com. They have delivery around the world in the shortest time and good service

The next project to be aware of must be teleportation,
When quantum computers are active a new problem with hit the lights.

You would be able to observe things that you could not even begin to imagine observing or altering  by mechanical manipulation.

It's to early to say Bitcoin would be safe.

What year on August? This year? :) I seconded that quantum is already a reality wayback before but its still on testing phase and i strongly believe it would still need more time to go in that era already. Hashes on some cryptos might be easily decoded but on bitcoin its still possible but would be a hard one. I dont know what would be the best added feature later on bitcoin when it comes to security but still its too early to mind up on these things. Just enjoy the stuffs as of now.

This is a great question and does need to be addressed by the community, although it won't be a reality until decades in the future.

In saying all that, along with all other replys here, quantum computers would have to be publically accessible for Bitcoin and other cryptos to be hacked. And I'm sure they'd be extremely expensive and possibly inaccessible to the public due to security issues.

It is too difficult for it to reach the community; it costs a great deal to implement this project, however, given the current situation of bitcoin, it is not strong enough to achieve that goal.

Not necessarily. There may be instances where the cryptographic primitives used in bitcoin are broken with quantum computing. But there are plenty of post-quantum cryptographic protocols being developed to secure the future if quantum computers continue to improve. There is also literature on e.g. quantum bitcoin protocol which implements these post-quantum crypto ideas to build quantum cryptocurrencies!

So if the public key is unknown there is no way, ever to compromise a private key (without hacking, etc) ?

This has always been my understanding.

I think, it is quite far for bitcoin owners to care about this quantum computing. The latter is in its embryonic stage. I wouldn't consider it a threat for like 4-5 years, really. ::)

We'd probably get quantum miners ,and some of the protection people disscused earlier in the thread

I do not believe this hypothesis, I believe that Crypto will evolve with development too.

It will not, as cryptos will move to new protocols that quantum computers cannot solve. Yes, quantum computers would speed up prime factorisation, but there are many mathematical problems that they will not improve upon compared to current computers.

When will that be readily available to the public though? Probably not for a very, very long time. Plus think about the expenses!

No, I do not think that quantum computing will kill cryptocurrency mining. In the very least, quantum computing is extremely expensive and is not something that is easily profitable. Each system currently costs around 10 million USD, and is not available to the average customer, provided you have the money to support what you wanted. However, quantum computing is still very much just developing and should not be considered as a possible threat for the next few years to come.

I think by the time bad actors, who are usually amateurish have access to quantum computers, banks will have responded with appropriate security measures. With that said I agree that communities like these will adopt quantum resistant security measures first. On top of that, down with the banks! Embrace decentralization!

It would not be surprising if the military has been using quantum computing/communication for years now. They are usually ahead of ordinary citizen technology by 10-20 years. The Nazis, for example built UFO-like flying aircraft in the 1940's. If you don't believe me search on YouTube. I bet 99.999% of people did not think there was such technology back then. They thought we would have flying cars today, but they actually had them back then!

Quantum computing certainly is a threat to crypto, yes. However, crypto in general has the potential to be uncrackable even with the aid of Quantum computing, so I would say cryptocurrency overall will not be killed, but and individual currencies that fail to adapt will be.

A very interesting topic here. These links are very useful and informative. Thanks

There are many years ahead to see quantum computers as home pcs. They will stay very experimental for long time I'm sure. So no problem for cryptocurrencies.

time will tell. Over time, everything will change, you can not talk now, we do not know the technology of the future.

It will first kill all the current encryption algorithms safeguarding e-commerce and banks.

So quantum-proof new algorithms will be developed. It's pretty easy for Bitcoin to hardfork to a new algorithm, and this wouldn't be a controversial hardfork.

  I think as these technologies develop, so too will crypto. People will figure out ways to prevent hacks due to quantum computing/teleportation, etc. The real thing that threatens cryptocurrency adoption are governments.
  See, if governments decide they do not want crypto to exist, they will simply block the major exchanges and Bitcoin-related sites and before you know it all your hopes of Bitcoin becoming mainstream will vanish.

Hmm let us hope this will never happen

Quantum computing has the ability to make any encryption obsolete and unusable. It poses a massive threat the cryptocurrency and any sort of protection in any way online. We are pretty far from this being a reality luckily so soak it in and buy low sell high now while you can. If you guys thought you'd seen a dump on the exchanges wait til you see the dump that comes once quantum computing is more of a reality.... :-[

Wow, this almost makes me want it to happen :D lol!

General purpose QC are working in the range of 1-4 qubits.
So definitely no.

Even in the future when we figured out everything regarding QC there is already post quantum cryptography.
So double no.

But this information is for the first time of our life and we will all be together with the arrival of pure enthusiasm is considered to be the second edition of pure spirit.

I believe that eventually it will happen. Quantum computers are no longer fiction

Will they be practical is another question. One analogy is a car that runs on water. It is no longer fiction for a long time now...But is it a good idea? No. Electric cars are. I say this because apparently Quantum Computing cannot do what traditional computers can do.

In any case, like everyone has been saying ,we have post-quantum cryptography.

All crypto without quantum resistance will be rendered obsolete, if it isn't already. The US had stealth fighters years before it was public if that is taken into consideration then one can assume crypto is already vulnerable to quantum computing.

I agree with that and it could become a great threat if it would once be possible to break the keys! What is a solving for this? Have the private key be 200 characters?

https://soundcloud.com/proofofbeats/quantum-badger

Quantum Computing will kill Crypto but it's not just because of security issues. It will kill Crypto because the very purpose of Crypto currency is to distribute processing. The virtually unlimited processing speed of a Quantum Computer will render distributed processing unnecessary.

Not a chance in the near term.  There are already protocols in place to protect from this type of intrusion. I would assume by the time Quantum computing is available to the masses there will be an equal countermeasure already in place across the crypto industry.

Quantum computing may be detrimental to Bitcoins unless individuals never spend bitcoins and just receive funds with an address for them to be safe since the hashing process protects the public-key used to create the address. At that point the funds may be at risk of attacks by new quantum computers.

About quantum computers - the methods of data encryption forge ahead, there are already cryptographic standards that are able to protect crypto-currencies from quantum computers... it is only the matter of time when they will be included into the protocol of the corresponding systems. Let us hope that developers won’t delay this and our crypto-wallets will be protected, when the quantum technic with huge calculating power appears  ;)

There are quantum resistant cryptographic algorithms. Blockchain protocols will be upgraded when necessary.

How can you know when is the time to "upgrade" protocols?

If such a quantum machine will ever be build, it will be a BIG secret for many many years, if not decades.
The greatest advantage of owning a machine capable of breaking crypto comes from no-one else knowing about it. So that everyone is using crypto, that they can break.

If it was public, it would soon be of no use.

Just look what happened with Enigma. After the war England even recommended some countries to use it, because it was unbreakable...  ;D
   

I am aware of no such "steps forward" to this point.  As of now it is still only a concept in labs.   It is so far into the future for now it's not really worth worrying about. Going from entangled particles to a real system which can run real software is nowhere in sight.

Its in the realm of controlled nuclear fusion,  it's going to change the world and the big breakthrough  is always just 10 years away and it's been that way for over 50 years.

I completely agree with you. It often happens that someone who has some secret wants to use the power of this secret as long as possible in order to be able to covertly affect the situation. There have already been many examples in history when this happened.

I have another question.
Lets say i have a quantum computer. Ive rent machine from IBM or something.
Will it be possible to decrease computation time for mining on such computer?
Till the point that it will be profitable?

I don't think so.

Quantum computing cannot make encryption methods devised with quantum computers obsolete and unusable....

Quantum computing will kill lots of old technologies, but it will give birth to many more - and better ones.

This thread is attracting a lot of spam and very very little thoughtful discussion, so it will be locked.