Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

IBM Q system in development with working 50 qubit processor

www-03.ibm.com

Post reply on HN
Print view View original

91–100 of 116 posts

Re: IBM Q system in development with working 50 qubit processor

#91

Post by Zaak »

rbanffy wrote: post #68
Zaak wrote: post #46

Earlier quoted context omitted.

Yeah, if you have a 5000-qubit computer and two people want to run 2000-qubit jobs, I can see them being able to run simultaneously. There will always need to be a classical computer running the quantum computer.

> There will always need to be a classical computer running the quantum computer. Not sure about the need, but it sure is convenient. Quantum computers are not always better for all kinds of problems and being able to route different jobs to different parts of the system should be an advantage. All this looks a lot like a digitally controlled analog computer or something that can program FPGAs on-the-fly.

A digitally controlled analog computer is a good analogy.

One big limitation of quantum computers is that they can't erase information without losing their quantumness. So simple things like if-then statements become impossible (you'd have to execute both branches every time).

Re: IBM Q system in development with working 50 qubit processor

#92

Post by bdamm »

eric-hu wrote: post #88

If quantum computing improves as it had been, how does this affect Bitcoin and ethereum as we now know it? Could the blockchain be compromised by a malicious actor who has much less than the majority?

My prediction: at some point Bitcoin will go through an upgrade process to transfer user wallets to a key pair based on a quantum resistant public key algorithm. Users will be given a time frame to transmit their coins to the new wallets, and after that time is expired, EC-based wallets will not be considered valid transaction sources any longer. Classic cash conversion in the digital age.

Re: IBM Q system in development with working 50 qubit processor

#93

Post by [deleted] »

vtomole wrote: post #55
Xeoncross wrote: post #43

Earlier quoted context omitted.

Wait, I didn't think we had actual quantum computers yet. https://en.wikipedia.org/wiki/Quantum_computing

We've had quantum computers since the 90's. We just haven't had "useful" quantum computers yet [0]. An implementation of quantum computers that is currently flourishing is one that is built out of superconducting circuits. This makes it easier to scale the quantum computer because you can leverage existing nanoelectronic fabrication techniques [1]. [0]: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing [1]:…

[deleted]

Re: IBM Q system in development with working 50 qubit processor

#94

Post by posixplz »

jest7325 wrote: post #83

How many qubit does it take to crack an AES 192 key?

Most postulations I've seen follow the axiom that the number of qubits must be no less than twice the number of bits used to generate the key. I found a pretty good summary of that thinking on StackExchange: https://security.stackexchange.com/questions/87345/how-many-...

Re: IBM Q system in development with working 50 qubit processor

#95

Post by roywiggins »

exikyut wrote: post #82
JepZ wrote: post #59

Presenting the pictures of a quantum computer with adbobe flash is an impressive combination of technologies. I hope they are use a different technology stack to develop the OS of that machine ;-)

Looks like their publishing platform is that old that it's still using Flickr's Flash photo embedding widget. TIL Flickr had such a widget.

Flickr's first incarnation was as a Flex app, if I remember right. The whole thing was Flash.

Re: IBM Q system in development with working 50 qubit processor

#97

Post by marcosdumay »

nategri wrote: post #89
marcosdumay wrote: post #34

Earlier quoted context omitted.

From the Wikipedia timeline[1], it seems to be growing linearly. 1 - https://en.wikipedia.org/wiki/Timeline_of_quantum_computing

To quote my thesis advisor's terrible joke: "Everything's linear to first order"

Not too long ago I summarized every datapoint in that page. It is almost perfectly linear (there's 1 qubit lower somewhere, 1 qubit higher elsewhere), the noise is way lower than anything I was expecting to see.

Re: IBM Q system in development with working 50 qubit processor

#98

Post by colejohnson66 »

kevin_thibedeau wrote: post #63
Xeoncross wrote: post #57

Earlier quoted context omitted.

> "We've had quantum computers since the 90's". It wasn't until 2005 we had the first (probable) qubyte created at the University of Innsbruck in Austria.

You don't need bytes to do computation.

Wouldn't a qubyte be 8 qubits?

Re: IBM Q system in development with working 50 qubit processor

#99

Post by IIAOPSW »

JepZ wrote: post #59

Presenting the pictures of a quantum computer with adbobe flash is an impressive combination of technologies. I hope they are use a different technology stack to develop the OS of that machine ;-)

Talking about the websites stack instead of the content is the HN equivalent of bike-shedding. It sounds like a contribution but it isn't.

https://en.wiktionary.org/wiki/bikeshedding

Re: IBM Q system in development with working 50 qubit processor

#100

Post by IIAOPSW »

eric-hu wrote: post #88

If quantum computing improves as it had been, how does this affect Bitcoin and ethereum as we now know it? Could the blockchain be compromised by a malicious actor who has much less than the majority?

I wrote an article about this pending publication so I can't link you just yet.

Bitcoin is mostly safe. Transactions in the pending pool can be compromised but quantum computers would need to perform logical operations at around 660 MHz. Confirmed transactions and unspent transactions are completely safe. The earliest quantum computers won't be fast enough to perform this attack. The problem is easily remedied by hard forking to replace ECDSA with a different public key system. There will be a lot of advanced warning.

I'm not sure on Ether.

Post reply on HN