#1 A new public key wouldn't defend against quantum brute forcing.
#2 Quantum computers attempt to achieve higher performance through increasing the data density of bits. Rather than exclusively utilizing binary digits with 0's and 1's as today's supercomputers do, quantum computers expand the number of base values utilized in the computational aspect of things. That's where their theoretical performance boost comes from.
A normal supercomputer could be characterized as a person who only has 2 fingers (bits) to count on. While a quantum supercomputer could theoretically have hundreds, thousands or more fingers (bits) which gives them a larger computational density.
I think quantum computers are equivalent to someone attempting to build a moped engine that can produce 200,000 horsepower while consuming the same amount of gasoline as a normal motor. They're supposed to be powered by breakthroughs in quantum physics which will likely never manifest.
I'm not sure mainstream readers would actually know that there could be a connection between quantum computers and Bitcoin unless it's explicitly mentioned in the article (and articles I've seen don't).
The entire premise of encryption is not that its unbreakable. But rather that it would take *too long* to break encryption for it to be feasible.
When tech corps like google release fake news claiming their "quantum computer" can solve problems in "200 seconds" that would take a normal supercomputer "10,000" years to solve.
That is a direct reference to existing encryption standards. That is a definite connection imo.
The quoted source says:
A trader, who wished to remain anonymous, said the price drop may have been exacerbated by margin calls and contract liquidations on Bitmex
Usually when this type of topic arises, people point out how single exchanges like bitmex do not represent a substantially significant trading volume. Not enough collective volume to significantly affect the value of bitcoin. There's a corresponding tendency towards arbitrage trading when the value of one commodity is significantly lower on one exchange than it is on another, which also helps to naturally prevents that occurrence via normal market mechanics.
Exchanges affecting price and volume are more typically associated with exchanges that historically carried no commissions on trades. That made it more feasible for market and price manipulation to be effective.
It makes plenty of sense for leveraged short calls on bitmex to concide with fake news that is likely to negatively affect bitcoin's price within the normalized vein of insider trading we've long witnessed in crypto trading. I think that is the most likely conclusion, and the one that will be adopted as more information becomes available.
Although there would seem to be a lot of coordinated market manipulation involved which traders might recognize. In terms of short selling and fear associated with most not being aware of the cause behind the price reduction.