You obviously don't know what the hell you are talking about in regards to quantum physics. And I don't have the time to educate you on a bitcoin forum. But let me just say a quantum computer could follow "Quantum Physics" and not the "same laws of physics as any other computer" like you mentioned. (I would love to see a regular computer use quantum entanglement for data transfers....lol) People who know quantum physics will understand what I just said.
People who know quantum physics are laughing at you right now. 
Topic: Quantum computer? So what! No worries...(?) - page 2. (Read 5047 times)
When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved.
Quantum physics suggests no such thing. Where'd you get that idea? Quantum computers aren't magical. They are limited by the same laws of physics as any other computer. It is completely impossible for a quantum computer to brute force a private key. The two quantum algorithms of interest to cryptanalysists (Shor's algorithm and Grover's algorithm) are interesting because they are not a brute force approach, instead they are a mathematical shortcut, in the same way that, say, a preimage attack is a shortcut.Shor's algorithm is only applicable to factorisation, or problems that can be generalised to factorisation. This includes most commonly used public-key cryptosystems, including ECC. However, there are public-key cryptosystems that cannot be broken this way, and Bitcoin could switch to such a system if necessary. Note also that no symmetic cypher or hash function is broken by Shor's algorithm.
Grover's algorithm is more general, but only speeds up the search by the square root of the keyspace, or to put it another way, the effective key size is halved. So a 256 bit key can be found in 2^128 steps instead of 2^256. However, 2^128 is still far too large to brute force, so 256 bit keys are still safe.
There's no such thing as magic.
Quote
Quantum physics suggests no such thing. Where'd you get that idea? Quantum computers aren't magical. They are limited by the same laws of physics as any other computer.
You might have misunderstood my comments in regards to quantum physics. But let me just say a quantum computer could follow "Quantum Physics" and not the "same laws of physics as any other computer" like you mentioned. (I would love to see a regular computer use quantum entanglement for data transfers....lol) People who know quantum physics will understand what I just said.
legendary
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When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved.
Quantum physics suggests no such thing. Where'd you get that idea? Quantum computers aren't magical. They are limited by the same laws of physics as any other computer. It is completely impossible for a quantum computer to brute force a private key. The two quantum algorithms of interest to cryptanalysists (Shor's algorithm and Grover's algorithm) are interesting because they are not a brute force approach, instead they are a mathematical shortcut, in the same way that, say, a preimage attack is a shortcut.Shor's algorithm is only applicable to factorisation, or problems that can be generalised to factorisation. This includes most commonly used public-key cryptosystems, including ECC. However, there are public-key cryptosystems that cannot be broken this way, and Bitcoin could switch to such a system if necessary. Note also that no symmetic cipher or hash function is broken by Shor's algorithm.
Grover's algorithm is more general, but only speeds up the search by the square root of the keyspace, or to put it another way, the effective key size is halved. So a 256 bit key can be found in 2^128 steps instead of 2^256. However, 2^128 is still far too large to brute force, so 256 bit keys are still safe.
There's no such thing as magic.
Thanks fox ! Can you please explain further how factorization applies to public key cryptography ?
Quantum on the picture does not seem to look like dumplings.
When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved.
Quantum physics suggests no such thing. Where'd you get that idea? Quantum computers aren't magical. They are limited by the same laws of physics as any other computer. It is completely impossible for a quantum computer to brute force a private key. The two quantum algorithms of interest to cryptanalysists (Shor's algorithm and Grover's algorithm) are interesting because they are not a brute force approach, instead they are a mathematical shortcut, in the same way that, say, a preimage attack is a shortcut.Shor's algorithm is only applicable to factorisation, or problems that can be generalised to factorisation. This includes most commonly used public-key cryptosystems, including ECC. However, there are public-key cryptosystems that cannot be broken this way, and Bitcoin could switch to such a system if necessary. Note also that no symmetic cypher or hash function is broken by Shor's algorithm.
Grover's algorithm is more general, but only speeds up the search by the square root of the keyspace, or to put it another way, the effective key size is halved. So a 256 bit key can be found in 2^128 steps instead of 2^256. However, 2^128 is still far too large to brute force, so 256 bit keys are still safe.
There's no such thing as magic.
Funny reading this thread. Known quantum computers can barely do a basic problem a 1950 calculator could do but everyone still speculates.
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
Factoring numbers is one thing. Solving a cryptographic hash is another. What's the connection?
Point is, quantum computing is so early in the stage that they can't even do basic math. When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved.
But there is no equation to undo a hash function.
Ok, I see what your getting at. But there still is a solution (answer) to the problem. And a theoretical fully working quantum computer could still try every possible solution at once.
legendary
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Funny reading this thread. Known quantum computers can barely do a basic problem a 1950 calculator could do but everyone still speculates.
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
Factoring numbers is one thing. Solving a cryptographic hash is another. What's the connection?
Point is, quantum computing is so early in the stage that they can't even do basic math. When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved.
But there is no equation to undo a hash function.
Funny reading this thread. Known quantum computers can barely do a basic problem a 1950 calculator could do but everyone still speculates.
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
Factoring numbers is one thing. Solving a cryptographic hash is another. What's the connection?
Point is, quantum computing is so early in the stage that they can't even do basic math. When the figure out how to harness quantum's potential then nothing will be safe. Factoring or cryptography or any other math mathematical equation will be done in minutes. Quantum physics suggest all solutions are attempted at once whereas a typical computer attempts to process a problem one step at a time until solved. What was your point? (I think I missed it)
legendary
Activity: 1302
Merit: 1008
Core dev leaves me neg feedback #abuse #political
Funny reading this thread. Known quantum computers can barely do a basic problem a 1950 calculator could do but everyone still speculates.
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
Factoring numbers is one thing. Solving a cryptographic hash is another. What's the connection?
Funny reading this thread. Known quantum computers can barely do a basic problem a 1950 calculator could do but everyone still speculates.
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
15 = 3 x 5 is the most they can calculate at this time in the game.
But if they ever do figure out quantum computing, bitcoin could be hacked in under an hour. It won't matter that the numbers are so large that typical computers would take longer than the age of the universe. Quantum computing essentially tries every possible solution at once.
http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time
legendary
Activity: 1302
Merit: 1008
Core dev leaves me neg feedback #abuse #political
http://www.quantrek.org/size_comparison/compare_local_stars.jpg
Arcturus might have enough power to brute force SHA 256
Arcturus might have enough power to brute force SHA 256
Haha nice.
http://www.quantrek.org/size_comparison/compare_local_stars.jpg
Arcturus might have enough power to brute force SHA 256
Arcturus might have enough power to brute force SHA 256
legendary
Activity: 1302
Merit: 1008
Core dev leaves me neg feedback #abuse #political
OP, all this discussed in many previous threads. Bottom line is
Yes, correct. No worries.
Yes, correct. No worries.
There is something that you are forgetting, when quantum computers are built, a new variation of protocol will have to be developed because quantum computers render difficulty at 0. Absolutely nothing. There would be no difficulty rating for a quantum computer. 
Nonsense. Only Grover's algorithm applies to the SHA hash of the blocks and thus difficulty of proof-of-work would not be adversely affected. The quantum computing threat is Shor's algorithm which applies to the elliptical cryptography used in the signatures of transactions.
There is something that you are forgetting, when quantum computers are built, a new variation of protocol will have to be developed because quantum computers render difficulty at 0. Absolutely nothing. There would be no difficulty rating for a quantum computer.
I thought that, that was a picture of the sun... 
That is a picture of a dust ball sample taken from Satoshi's hind end.
OROBTC, I had already explained to you before in that other thread you started. That is a nonsense claim about a thermodynamic limitation for quantum computing attack:
https://bitcointalksearch.org/topic/m.5562217
They correctly assert that a brute force attack would exceed fathomable entropy (thermodynamic) limitations. However, what they fail to tell you is that Shor's algorithm isn't a brute force attack. Shor's algorithm takes advantage of the fact that in quantum computing the computation is unfathomably parallelized.
https://bitcointalksearch.org/topic/m.5562217
Here is an excellent article on this quantum computing topic and also explains how Bitcoin's three encryption methods are combined, so it is relevant to this thread's title as well:
http://www.bitcoinnotbombs.com/bitcoin-vs-the-nsas-quantum-computer/
There are two things I dispute from the article.
Nonsense. Shor's algorithm is not a brute force attack. The author inserted this disinformation into his otherwise good article, because most users don't understand that Shor's algorithm doesn't require a brute force capability.
http://www.bitcoinnotbombs.com/bitcoin-vs-the-nsas-quantum-computer/
There are two things I dispute from the article.
Quote
Let’s consider the type attack most people think of when hear of quantum computers―a brute force attack.
Nonsense. Shor's algorithm is not a brute force attack. The author inserted this disinformation into his otherwise good article, because most users don't understand that Shor's algorithm doesn't require a brute force capability.
They correctly assert that a brute force attack would exceed fathomable entropy (thermodynamic) limitations. However, what they fail to tell you is that Shor's algorithm isn't a brute force attack. Shor's algorithm takes advantage of the fact that in quantum computing the computation is unfathomably parallelized.
quantum create ... difficulty rise 
bitcoin is formidable. 
bitcoin is formidable. 
Just remember, this is the difficulty of cracking encryption using brute-force. If a new technique or "short-cut" is ever discovered, this entire thing could be moot.
A note about quantum computers: the type of quantum computer that can crack encryption is one which runs Shor's Algorithm. Shor's Algorithm allows the computer to crack encryption in polynomial time, which drastically speeds the process. Bitcoin relies on several different forms of encryption, however, only one of which (ECDSA--which secures your wallets) would be crackable with Shor's Algorithm. SHA-256 and RIPEMD-160 would remain unaffected.
Also, the only wallets which would be vulnerable would be those that had spent money. Unused wallets would not be vulnerable. Moving the protocol over to Lamport Signatures would pretty much solve the problem entirely, in any event.
A note about quantum computers: the type of quantum computer that can crack encryption is one which runs Shor's Algorithm. Shor's Algorithm allows the computer to crack encryption in polynomial time, which drastically speeds the process. Bitcoin relies on several different forms of encryption, however, only one of which (ECDSA--which secures your wallets) would be crackable with Shor's Algorithm. SHA-256 and RIPEMD-160 would remain unaffected.
Also, the only wallets which would be vulnerable would be those that had spent money. Unused wallets would not be vulnerable. Moving the protocol over to Lamport Signatures would pretty much solve the problem entirely, in any event.
I thought that, that was a picture of the sun...
I also think so, what is it? It's a picture of the sun, just to show the amount of energy.
I could be wrong here (though I doubt it) but a more knowledgeable member can verify...
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