Quote from: AverageGlabella on June 25, 2019, 10:52:21 AM

Quote from: arcmetal on June 25, 2019, 09:50:51 AM

If you are worried that a quantum computer can cause a collision with a bitcoin private key (like finding a key with someone's bitcoin), sure it could be possible. But I do like reading about what an incredible machine it would take to do this. Here is a great thread on this topic:
https://bitcointalk.org/index.php?topic=5147514.msg51224295#msg51224295

Essentially they describe how if someone where to build a big enough computer to crack bitcoin in 2 minutes, say, maybe with a large "quantum computer", the bitcoin code can be upgraded to then make it near impossible again for that new machine to crack it. The code can always stay ahead of the hardware.

Just like personal computers used to be the size of the room do you think that quantum computers in the next 20 years will be able to downgrade their size to almost the size of a personal computer? Whenever discussion comes up with quantum computers Bremermann's limit always seems to be the counter argument to those defending Bitcoin's race against quantum computers. The thread you linked seems to have mentioned it fairly early on but that thread puts into perspective just how big the computer would have to be. The only argument is that we get better at producing and manufacturing quantum computers and downsize them.

I have the opinion that quantum computers will only bring positive change to Bitcoin and increase its security by changing to a different algorithm capable of outlasting quantum computers evolution. Its not like quantum computers will be increasing their power at a exponential growth that we won't be able to deploy quantum resistant algorithms.

Correct. I don't believe I'll see, in my lifetime, a so called quantum computer big enough to take down bitcoin in its current state. As we agree, long before any large and powerful machine is constructed, the algorithms for bitcoin can be upgraded to deal with such a threat long before that hardware exists.