Quantum computers are unlikely to threaten Bitcoin in the near future, according to developer and Casa founder Jameson Lopp.
The discussion becomes more intense if quantum computers can soon become so advanced that they threaten the cryptosystems that protect blockchains like Bitcoin and Ethereum.
Experts disagree on when quantum computers may threaten Bitcoin
In a post on X (formerly Twitter), Lopp wrote that quantum computers will not destroy Bitcoin soon.
“No, quantum computers will not destroy Bitcoin in the near future. We will continue to monitor developments… We should hope for the best but prepare for the worst,” wrote Lopp in a post.
Lopp's view on the timeline aligns with what many experts think. They argue that quantum computers are not an immediate threat to the network. Adam Back, CEO of Blockstream, recently stated that the short-term risk is “negligible.”
“All of this is decades away. It is far too early, and they have major research problems in all applied physics needed to even determine if it is possible on a larger scale. But it is good to be ‘ready for quantum computers’ anyway,” Back said in a post.
Charles Hoskinson, founder of Cardano, also has a similar opinion. He argues that today's threats from quantum computers are exaggerated and not urgent right now. Hoskinson also pointed out that blockchains can switch to quantum-resistant cryptography, but it would make the systems much less efficient.
But some experts believe the threat is approaching. David Carvalho, CEO of Naoris Protocol, has warned that quantum computers could threaten Bitcoin's security within 2 to 3 years.
Michele Mosca, a researcher at the University of Waterloo, estimated a chance of 1 in 7 that major cryptosystems are broken as early as 2026.
On Metaculus, the expected time for when quantum computers can crack one of the RSA numbers has also become shorter. It is now believed that it could happen as early as 2034 instead of 2052.
The Quantum Doomsday Clock project is even more alarming. There, it is estimated that quantum computers will break Bitcoin's encryption before March 8, 2028.
Why it is difficult to make Bitcoin quantum safe
Experts do not agree on the timeline, but many agree on one thing. If Bitcoin needs to be upgraded to quantum-resistant technology, it will take a long time. Lopp mentions that such a transition can take 5 to 10 years.
When someone asked why the discussion about quantum computers mostly revolves around Bitcoin and not banks, Lopp explained that the difference lies in how quickly the systems can be upgraded.
“Banks can upgrade their systems much faster than the Bitcoin network,” he said in a post.
At the same time, another market analyst explained why it is harder to make blockchains quantum-resistant than centralized systems.
“For the banking sector and the internet, it is much easier to change technology. When crypto standards change, they can implement new algorithms through coordinated updates. They can revoke old keys, provide new logins, and even force users to switch,” he wrote in a post.
Bitcoin, on the other hand, lacks a central instance that can decide on such changes. To switch to quantum-resistant signatures requires broad consensus in the community, organized technical coordination, and voluntary participation from users.
The analyst pointed out that lost or inactive Bitcoins and wallets cannot be upgraded. Therefore, a portion of Bitcoin's supply will always be vulnerable if quantum attacks become possible. Technical limitations make it even more difficult.
“Most signature systems that are quantum-resistant have much larger keys and signatures than ECDSA. In a system that is already limited by block sizes and global repetition, this becomes a significant change. An additional workload that banks can handle is a much greater challenge on the blockchain,” it stated in the post.
Thus, the same decentralization that protects and strengthens Bitcoin also makes it harder and slower to adapt the cryptography than in centralized systems.
