Strong encryption turning into weak encryption is a severe problem, but it's a manageable and resolvable one also. The ease of exploiting quantum encryption-breaking might not be comparable to exploiting a public ledger of trust like the blockchain.
If BTC has a multi-trillion-dollar market cap, and quantum exploitation occurs, the only thing that backs the currency (trust) vanishes, and the values quickly drops to zero.
If we are reliant on BTC for global finances in the future, as many are proposing, this could result in a global depression.
This might be the single biggest problem quantum computing could bring us, short of the "talking to alternate universes" theoretical use cases some people are talking about (that probably won't happen).
Encrypted data can be re-encrypted to be quantum-secure. The vulnerability is temporary
A compromised blockchain dies forever. A brand new quantum-secure blockchain would need to be invented.
If BTC has a multi-trillion-dollar market cap, and quantum exploitation occurs, the only thing that backs the currency (trust) vanishes, and the values quickly drops to zero.
If we are reliant on BTC for global finances in the future, as many are proposing, this could result in a global depression.
This might be the single biggest problem quantum computing could bring us, short of the "talking to alternate universes" theoretical use cases some people are talking about (that probably won't happen).
Encrypted data can be re-encrypted to be quantum-secure. The vulnerability is temporary
A compromised blockchain dies forever. A brand new quantum-secure blockchain would need to be invented.