I'm so glad I asked this question. Not only have I received tons of valuable feedback, but I've been inspired to carry out some more research on the topic. I used to have Flipboard directly connected my phone where I would never miss a scientific publication on anything. I need to get that set up again.
Quantum computers are still in development, infancy stage. The most dangerous attack by quantum computers is against public-key cryptography. Bitcoin ECDSA algorithm would be broken. A quantum computer could easily decrypt the private key using the public key.
Quantum computers are in their infancy yes. But, with how fast technology is accelerating, infants become full grown faster than ever.
As of 2016, the largest general-purpose quantum computers have fewer than 10 qubits. Attacking Bitcoin keys would require around 1500 qubits.
A team in the US has created a simulator with 51 quantum bits – the largest of its kind so far. Mikhail Lukin at Harvard University announced the achievement on 14 July at the International Conference on Quantum Technologies in Moscow.I know a simulator is not running the computations of a fully functioning quantum computer. It just supports the fact that such a system could now be built. Using simulators just saves tons of money and resources.
A new public-key algorithm can be added to Bitcoin as a softfork. From the end-user perspective, this would appear as the creation of a new address type, and everyone would need to send their bitcoins to this new address type to achieve quantum security.
That is more good news on this topic. I was unaware the this would be so easy to implement. Considering all the fuss about the recent Hard Fork. It was like Y2K all over again.
Quantum computers wouldn't affect block creation, but they would have a huge advantage over other mining hardwares, they would be mining majority of the blocks. If in future quantum computers are available publicly then it's somewhat fair, but imagine if government agencies or other organizations jumped into mining with quantum computers.
That is definitely going to be an issue. I'm not too concerned about the government capitalizing on this opportunity as their control over new technology slipped out of their grasps years ago. It's the private companies that are making the most advancements from what my civilian eyes can see. But who really knows?
Thank you and everyone else who chimed in on this topic. Your insight and expertise have been noted and appreciated.