Topic: Quantum computer? - page 2. (Read 13009 times)
AFAIK quantum computers are hypothesized to solve the factoring problem, but not the discrete logarithm and SHA256 hash collision problems bitcoin security depends on.
That's the kind of quantum computer i had in mind.
The regular currencies can adapt, by using symmetric cryptography at the expense of usability for example
The regular currencies can adapt, by using symmetric cryptography at the expense of usability for example
They can't. Or rather, the secure Internet infrastructure is based on asymmetric cryptography (HTTPS). Quantum computer would break this infrastructure until most Internet users would have quantum computers which would use asymmetric cryptography algorithms adapted to the new technology.
That's the kind of quantum computer i had in mind.
The regular currencies can adapt, by using symmetric cryptography at the expense of usability for example, but what would become of purely electronic thing like bitcoins are?
The regular currencies can adapt, by using symmetric cryptography at the expense of usability for example, but what would become of purely electronic thing like bitcoins are?
Let's say i have a practicable quantum computer or other device capable of rapid factorization of large enough integers.
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
If you had any system, quantum or not, that could solve the discrete logarithm problem, yes, you could generate the private key from any known public key. With that you could steal any coins you want.
However, you could also probably steal most of the Dollars, Euros, Roubles, etc.
Classical computers work linearly, executing a specific set of instructions. Quantum computing works by setting up a "situation", and then letting it evolve naturally in a quantum physical way, exploring multiple solutions at once.
Think of it like this: A classical computer acts like a plinko machine. You put a ball at the top in one of the possible positions, and it clunks down each step until it gets to the bottom. A quantum computer puts a ball at the top in EVERY position, and lets it fall, until it finds the best one.
The trouble is setting up the situation in a very careful way, such that the interferences between different particles is used to your advantage in the calculation.
Think of it like this: A classical computer acts like a plinko machine. You put a ball at the top in one of the possible positions, and it clunks down each step until it gets to the bottom. A quantum computer puts a ball at the top in EVERY position, and lets it fall, until it finds the best one.
The trouble is setting up the situation in a very careful way, such that the interferences between different particles is used to your advantage in the calculation.
Haven't found much on the topic there, so asking away.
Let's say i have a practicable quantum computer or other device capable of rapid factorization of large enough integers.
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
With a device of this kind i can get the private key from public key, right?
So after receiving a bitcoin from someone, can i subsequently successfully fake a transfer of all there was on his side?
Let's say i have a practicable quantum computer or other device capable of rapid factorization of large enough integers.
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
With a device of this kind i can get the private key from public key, right?
So after receiving a bitcoin from someone, can i subsequently successfully fake a transfer of all there was on his side?
I would say no to all questions because quantum computing is not like a magic converter. If you have a working quantum computer, you won't be able to feed in BitCoin hashes and spit out Private Keys. I think it would fall under the hashing collision topics here more than trying to factor large integers. While the media makes quantum computers seem like they will operate like a 1 Trillion MHz processor, they actually operate in a specialized way that is kind of hard to explain in terms of computer science.
Haven't found much on the topic there, so asking away.
Let's say i have a practicable quantum computer or other device capable of rapid factorization of large enough integers.
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
With a device of this kind i can get the private key from public key, right?
So after receiving a bitcoin from someone, can i subsequently successfully fake a transfer of all there was on his side?
Let's say i have a practicable quantum computer or other device capable of rapid factorization of large enough integers.
What are the consequences to a developed bitcoin network?
Any way it could let me cheat in generation?
Any way it would let me cheat in transactions?
With a device of this kind i can get the private key from public key, right?
So after receiving a bitcoin from someone, can i subsequently successfully fake a transfer of all there was on his side?
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