Quantum money using knots

[Mike Hearn]

Here's an interesting paper on what is effectively a BitCoin-ish like scheme using quantum computers.

http://www2.lns.mit.edu/~avinatan/research/knot_money_arxiv.pdf

Quantum money is a cryptographic protocol in which a mint can produce a quantum state, no one else can copy the state, and anyone (with a quantum computer) can verify that the state came from the mint. We present a concrete quantum money scheme based on superpositions of diagrams that encode oriented links with the same Alexander polynomial. We expect our scheme to be secure against computationally bounded adversaries.

[LZ]

I do not think it can be useful in the near future, but we at least have to think about it.
Also what do you think: can we create Quantum Bitcoin compatible with the main chain?

[BitterTea]

Also what do you think: can we create Quantum Bitcoin compatible with the main chain?

Doesn't matter... electronic currencies are easily exchangeable. Competition is good.

[Mike Hearn]

No, they wouldn't be compatible.

Quantum computing is something that has made great theoretical advances in the literature but actually obtaining qubits is tricky and expensive. I have no idea how close quantum knot based money might be to reality, but for somebody to trust a money system they have to understand it and we're many years away from having a critical mass of people who are capable of understanding and thus trusting such a system. Unless it was imposed from above by governments or official mints I doubt it'd take off.

BitCoin has a similar problem of course but the number of people who can understand Satoshis paper is probably way, way higher than the number who can understand this one.

[nofuture]

This is a really cool paper but of no practical value.  There is also a video that expounds upon the paperon Google Video called quantum money.    Very fascinating stuff.  But no one except the authors understands the proposal and they don't know if someone hasn't found a flaw in it.  If a genius like Peter Shor is still struggling with the theory you can forget about quantum money coming to fruition in whats left of our lifetimes.   

http://www.google.com/url?sa=t&source=web&cd=1&sqi=2&ved=0CBoQtwIwAA&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DHaJEDyahLZY&ei=iKs0TZqzO4LZgAeTm6TZCw&usg=AFQjCNFmqXsLDXb6BOceFB6uoQglJi6C-Q



Even the knots thing is just a proposal to get quantum money (first proposed in 69) off the ground. No one has proven that will will work.  And if the theory was proven the technology to implement this even if it does work does not exist.   We don't have quantum computers and we don't have a quantum internet.     

Bitcoin works on existing infrastructure and works on technology that exists now.   Bitcoin is cutting edge technology.  You need a PhD in applied mathematics computer science and cryptography to understand how it works in detail.   It is difficult enough for the average Joe to understand just the practical side of Bitcoin.  They will learn to trust it and embrace it on reputation alone.   Quantum money is so far out it might as well be talking about Teleporters and Warp Drives (Star Trek). 

[Hal]

This would be a centralized system anyway. It's basically equivalent to a bank issuing digital money in the form of PK signatures, but because it's quantum it's theoretically more secure. You'd still be trusting the bank/mint not to cheat or inflate.