What Happens to Bitcoin's Security After Quantum Computing is Perfected?

[CHRISBIN702]

This is something I think about often and it is a big concern of mine. This technology, though in its infancy, has the ability to decipher cryptographically encrypted algorithms in a fraction of the time. This could be catastrophic to crypto-currency as we currently practice it. There is a team of researchers that claim to have made a 51 Qubit quantum computer.
As of right now, Quantum supremacy is still hypothetical but Google has announced that it expects to achieve quantum supremacy by the end of 2017, and IBM says that the best classical computers will be beaten on some task within about five years.
Is there or has there or will there be any systems in place to be ready for this regarding Bitcoin and Crypto-currency. Not only are your coins at stake but the entire Crypto-currency eco-system is at stake.
Any thoughts?
Chris Butler, Community Regional Manager for RunCPA
Here is an example of a Qubit next to a bit.

[1715280593]

1715280593

[1715280593]

1715280593

[1715280593]

1715280593

[1715280593]

1715280593

[1715280593]

1715280593

[hatshepsut93]

Quantum computers are being developed gradually, it will take some time for them to be able to crack ECDSA cryptography. By that time we might already have a hardfork that will change current public-private key algorithm of Bitcoin to something quantum-resistant. Also, you should know that Satoshi foresaw the risk of vulnerability in ECDSA, so public keys are also protected in Bitcoin - they are encrypted with SHA256, and only get exposed after an output is spent. So, even if someone will secretly have a powerful quantum computer, they won't be able to destroy Bitcoin by hacking everyone's coins.

[digaran]

Quantum computers only could join the mining and we all know how that works, more hash power you point to the network the difficulty adjusts itself to make average block generation time around 10 minutes, how to store Bitcoins and where to store them is not the concern of Bitcoin and it's security.
One could use multi signature addresses, in the future there will be Quantum resistance implementations as well. but seriously Bitcoin can't be hacked no matter what, no matter how good the your excuses are, said Gmaxwell.

[Decoded]

Perfected? Classic computing hasn't even been perfected yet.

Quantum computers, at least our current versions of them, are extremely limited in functionality. Bitcoin's encryption standards certainly aren't quantum-proof, but they aren't the easiest to crack, either. Hopefully by the time they are powerful and versatile, we will have moved to a standard that is built for quantum computers.

[Creepings]

Most of the people here in the forum are taking informations on how they can keep their bitcoins safe. If this is the case, I think they will be trying to protect more their bitcoins. I will take this as a positive effect on bitcoin users rather than negative. And I think the developer won't just sit there and let this computers do what they want with their projects and digital currencies.

[darkangel11]

And again the quantum discussion begins This used to be an issue every single year since the term popped out and every time it was answered in the same manner.
Yes, quantum computing could break sha256, but by the time it's possible to use it the bitcoin network will surely be upgraded. We don't even know if it will be the main cryptocurrency. If you can decypher a key, you can also use the same computer to make a much longer and more secure one.
There's really nothing to worry about at the moment.

[aleksej996]

Probably not much. Quantum computers are good at breaking public/private keys not at breaking hashes, best practices in bitcoin is to use a different address for every pair of transactions. So you should not send from same address twice. This would keep your public key secret until the transaction is sent, since the addresses are the encoded hash values of public keys, by that time even a quantum computer will not have the time to compromise it until it gets confirmed.

Quantum computers are being developed gradually, it will take some time for them to be able to crack ECDSA cryptography. By that time we might already have a hardfork that will change current public-private key algorithm of Bitcoin to something quantum-resistant. Also, you should know that Satoshi foresaw the risk of vulnerability in ECDSA, so public keys are also protected in Bitcoin - they are encrypted with SHA256, and only get exposed after an output is spent. So, even if someone will secretly have a powerful quantum computer, they won't be able to destroy Bitcoin by hacking everyone's coins.

Hardfork is not needed. ECDSA are in scripts of transactions. We would just add more nonstandard scripts. I believe all the transactions should still be valid, but old clients wouldn't know how to withdraw coins or send them securely using new scripts.

And again the quantum discussion begins This used to be an issue every single year since the term popped out and every time it was answered in the same manner.
Yes, quantum computing could break sha256, but by the time it's possible to use it the bitcoin network will surely be upgraded. We don't even know if it will be the main cryptocurrency. If you can decypher a key, you can also use the same computer to make a much longer and more secure one.
There's really nothing to worry about at the moment.

No it can't. At least not more efficiently then classical computers.

[mkhlslkhnv]

If ECDSA could be hacked by quantum computer with high probability, treat for SHA-256 is more theoretical. We have enough time,and cryptography is evolving, and will be evolving with the evolving of quantum computers.
In my view, bitcoin have some other important problems  

[CHRISBIN702]

Thank you all for your input. I feel a little better now. I see the confidence in the Bitcoin network in these few posts and it gives me hope. The only thing that still concerns me is Google's recent claims of achieving quantum supremacy by the end of 2017. It's damn near the end of 2017. If any of you follow the advances in quantum computing, you should know that Google is a quantum research powerhouse, both theoretical and applied, so their claims should not be taken lightly.

[Soros Shorts]

If ECDSA could be hacked by quantum computer with high probability, treat for SHA-256 is more theoretical. We have enough time,and cryptography is evolving, and will be evolving with the evolving of quantum computers.
In my view, bitcoin have some other important problems  

By not reusing addresses the weakest link in the chain  (ECDSA) remains protected by a hash operation because the public key remains hidden until such a time when the coins in that address is spent. Once you spend the coins fromantic and address, discard the address because the public key has been revealed and the private key now is theoretically open to a quantum attack.

[CHRISBIN702]

If ECDSA could be hacked by quantum computer with high probability, treat for SHA-256 is more theoretical. We have enough time,and cryptography is evolving, and will be evolving with the evolving of quantum computers.
In my view, bitcoin have some other important problems  

By not reusing addresses the weakest link in the chain  (ECDSA) remains protected by a hash operation because the public key remains hidden until such a time when the coins in that address is spent. Once you spend the coins fromantic and address, discard the address because the public key has been revealed and the private key now is theoretically open to a quantum attack.

OK thank you very much. I understand now how to protect myself. Hopefully, more people read this and not use the same address more than once.

[krishnapramod]

This is something I think about often and it is a big concern of mine. This technology, though in its infancy, has the ability to decipher cryptographically encrypted algorithms in a fraction of the time. This could be catastrophic to crypto-currency as we currently practice it. There is a team of researchers that claim to have made a 51 Qubit quantum computer.
As of right now, Quantum supremacy is still hypothetical but Google has announced that it expects to achieve quantum supremacy by the end of 2017, and IBM says that the best classical computers will be beaten on some task within about five years.
Is there or has there or will there be any systems in place to be ready for this regarding Bitcoin and Crypto-currency. Not only are your coins at stake but the entire Crypto-currency eco-system is at stake.
Any thoughts?
Chris Butler, Community Regional Manager for RunCPA
Here is an example of a Qubit next to a bit.

Quantum computers are still in development, infancy stage. The most dangerous attack by quantum computers is against public-key cryptography. Bitcoin ECDSA algorithm would be broken. A quantum computer could easily decrypt the private key using the public key.

As of 2016, the largest general-purpose quantum computers have fewer than 10 qubits. Attacking Bitcoin keys would require around 1500 qubits.

Bitcoin already has some built-in quantum resistance. If you only use Bitcoin addresses one time, which has always been the recommended practice, then your ECDSA public key is only ever revealed at the one time that you spend bitcoins sent to each address. A quantum computer would need to be able to break your key in the short time between when your transaction is first sent and when it gets into a block. It will likely be decades after a quantum computer first breaks a Bitcoin key before quantum computers become this fast.

A new public-key algorithm can be added to Bitcoin as a softfork. From the end-user perspective, this would appear as the creation of a new address type, and everyone would need to send their bitcoins to this new address type to achieve quantum security.

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

The other risk is quantum computers would drastically increase the mining difficulty.

As more miners join, the rate of block creation will go up. As the rate of block generation goes up, the difficulty rises to compensate which will push the rate of block creation back down.

Quantum computers wouldn't affect block creation, but they would have a huge advantage over other mining hardwares, they would be mining majority of the blocks. If in future quantum computers are available publicly then it's somewhat fair, but imagine if government agencies or other organizations jumped into mining with quantum computers.

If in future quantum computers happens to threaten bitcoins security new cryptography algorithms can be incorporated into bitcoin protocol to prevent this.

[CHRISBIN702]

I'm so glad I asked this question. Not only have I received tons of valuable feedback, but I've been inspired to carry out some more research on the topic. I used to have Flipboard directly connected my phone where I would never miss a scientific publication on anything. I need to get that set up again.

Quantum computers are still in development, infancy stage. The most dangerous attack by quantum computers is against public-key cryptography. Bitcoin ECDSA algorithm would be broken. A quantum computer could easily decrypt the private key using the public key.

Quantum computers are in their infancy yes. But, with how fast technology is accelerating, infants become full grown faster than ever.

As of 2016, the largest general-purpose quantum computers have fewer than 10 qubits. Attacking Bitcoin keys would require around 1500 qubits.

A team in the US has created a simulator with 51 quantum bits – the largest of its kind so far. Mikhail Lukin at Harvard University announced the achievement on 14 July at the International Conference on Quantum Technologies in Moscow.

I know a simulator is not running the computations of a fully functioning quantum computer. It just supports the fact that such a system could now be built. Using simulators just saves tons of money and resources.

A new public-key algorithm can be added to Bitcoin as a softfork. From the end-user perspective, this would appear as the creation of a new address type, and everyone would need to send their bitcoins to this new address type to achieve quantum security.

That is more good news on this topic. I was unaware the this would be so easy to implement. Considering all the fuss about the recent Hard Fork. It was like Y2K all over again.

Quantum computers wouldn't affect block creation, but they would have a huge advantage over other mining hardwares, they would be mining majority of the blocks. If in future quantum computers are available publicly then it's somewhat fair, but imagine if government agencies or other organizations jumped into mining with quantum computers.

That is definitely going to be an issue. I'm not too concerned about the government capitalizing on this opportunity as their control over new technology slipped out of their grasps years ago. It's the private companies that are making the most advancements from what my civilian eyes can see. But who really knows?

Thank you and everyone else who chimed in on this topic. Your insight and expertise have been noted and appreciated.

[dothebeats]

That's why Satoshi and other bitcoin devs always advise people not to use the same address more than once. If an address spend the coins that it contains, that is the time when the public key is exposed and the private key could somehow be cracked by quantum computing.

But tbh, I'm guilty of reusing the same address over and over again.

[Yakamoto]

Quantum computers only could join the mining and we all know how that works, more hash power you point to the network the difficulty adjusts itself to make average block generation time around 10 minutes, how to store Bitcoins and where to store them is not the concern of Bitcoin and it's security.
One could use multi signature addresses, in the future there will be Quantum resistance implementations as well. but seriously Bitcoin can't be hacked no matter what, no matter how good the your excuses are, said Gmaxwell.

Wouldn't making the target time of the blockchain 10 minutes, while having quantum computing being a factor within the mining, mean that the difficulty would scale up infinitely? Hypothetically 10 minute target times would mean nothing because the computer could send any and all combinations to the nodes at once and find the blocks, meaning that the difficulty would never truly be able to beat quantum computing. All other miners would find their investments becoming paperweights (in the context of bitcoin mining) within a few hours, again assuming quantum computing operates in the same manner that it is "expected" to operate with.

[Hydrogen]

AFAIK if true quantum computing is developed, encryption standards will be upgraded to quantum levels to secure against brute forcing.

Its probably more cost effective to build a cloud of existing hardware built specifically to brute force encryption than to undertake the pioneering of a theoretical field like quantum computing.

Quantum computers are similar to fusion energy in that there is a lot more theoretical abstraction than actual results in those fields.

[chixka000]

Quantum computers are being developed gradually, it will take some time for them to be able to crack ECDSA cryptography. By that time we might already have a hardfork that will change current public-private key algorithm of Bitcoin to something quantum-resistant. Also, you should know that Satoshi foresaw the risk of vulnerability in ECDSA, so public keys are also protected in Bitcoin - they are encrypted with SHA256, and only get exposed after an output is spent. So, even if someone will secretly have a powerful quantum computer, they won't be able to destroy Bitcoin by hacking everyone's coins.

That was a great point. They can maybe alter the transaction process but hacking a peer to peer bitcoin is really not that possible they have to hack in millions of users with encrypted data for each individual.

[krishnapramod]

Bitcoin developer will make new BIP which replace ECDSA with something else that can't be cracked with Quantum Computer and plan fork few months after the BIP is announced and spread the info to bitcoiner.

As of 2016, the largest general-purpose quantum computers have fewer than 10 qubits. Attacking Bitcoin keys would require around 1500 qubits.

Bitcoin already has some built-in quantum resistance. If you only use Bitcoin addresses one time, which has always been the recommended practice, then your ECDSA public key is only ever revealed at the one time that you spend bitcoins sent to each address. A quantum computer would need to be able to break your key in the short time between when your transaction is first sent and when it gets into a block. It will likely be decades after a quantum computer first breaks a Bitcoin key before quantum computers become this fast.

A new public-key algorithm can be added to Bitcoin as a softfork. From the end-user perspective, this would appear as the creation of a new address type, and everyone would need to send their bitcoins to this new address type to achieve quantum security.

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

The other risk is quantum computers would drastically increase the mining difficulty.

I don't understand why would it's risk since mining difficulty adjusted every 2 weeks with current hashrate power and block keep mined every 10 minutes, unless mining hashrate suddenly incrased more than +50% in short time.

Bitcoin mining is also dependent on SHA256. Bitcoin miners must find solutions to specially designed hashing problems in order to authenticate transactions on the blockchain and be rewarded with newly created Bitcoins. However, quantum computers could potentially take advantage of Grover’s algorithm for a quadratic speedup in hashing, basically halving key lengths. This could be used as an advantage in Bitcoin mining, as it would greatly speed up the rate by which a miner using a quantum computer could find solutions.

https://www.smithandcrown.com/8655/

Would quantum computers speed up hashing? Maybe or may not be. Difficulty would increase, but still it would be 10 minutes per block, but if quantum computer does have a speed advantage then it is a threat. Just a hypothesis, might happen, might not and surely not in the near future.

[guoyu78]

Every new invention has a weakness or in other words all tricks do have a blind spot. Bitcoins will face many problems in its journey and there will always be a solution. Quantum computer are definitely a bad news for bitcoin community but let’s just hope new methods and also will be developed in order to beat this hurdle. Surely, the crypto currency technology will also improve with time.