An interesting discussion here. The good thing is that if necessary, the crypto algorithm used by Bitcoin can be updated without too much work. Provisions are already in place and this has been demonstrated by the Scrypt-based forks of Bitcoin, like Litecoin.
I can already hear the cries of "Quantum computers are ruining Bitcoin!" which will of course follow the current echoes of "ASICs are ruining Bitcoin!" which were preceded by the lamentation "GPUs are ruining Bitcoin!"
I can already hear the cries of "Quantum computers are ruining Bitcoin!" which will of course follow the current echoes of "ASICs are ruining Bitcoin!" which were preceded by the lamentation "GPUs are ruining Bitcoin!"
Precisely. People are already talking quite a bit about QCs and we're arguably dozens of years from practical general quantum computing. By the time they're on the near horizon, the hooks in Bitcoin and all other widespread forms of electronic cryptography will be undergoing major renovation. Think Y2K -- it's not something that can catch us off guard because we can see it coming as the research advances.
This is not to say other disruptive technologies couldn't severely compromise cybersecurity at any time along the way, as they have in the past.