“You should have a few good years ahead of you but I wouldn’t hold my Bitcoin,” Peronnin said, laughing. “They need to fork [move to a stronger blockchain] by 2030, basically. Quantum computers will be ready to be a threat a bit later than that,” he said.

Quantum doesn’t just threaten Bitcoin, of course, but all banking encryption. And it is likely that in all these cases companies are developing quantum resistant tools to upgrade their existing security systems.

Defensive security algorithms are improving, Peronnin said, so it’s not certain when the blockchain will become vulnerable to a quantum attack. But “the threshold for such an event is coming closer to us year by year,” he said.