A claim has emerged that if Bitcoin (BTC) shifts to a post-quantum system in the future, it could reveal the amount of bitcoin Satoshi Nakamoto can actually access. At the same time, calls are growing for Bitcoin to prepare a path to quantum-resistant cryptography starting now, even if the threat from quantum computers does not become an immediate reality.

Cointelegraph, a blockchain outlet, reported on Wednesday that Adam Back (아담 백), chief executive of Bitcoin technology company Blockstream, said at Paris Blockchain Week that the safest approach is to design in advance an optional upgrade that lets Bitcoin move to quantum-resistant cryptography if needed. He also said such a change in address format could become an opportunity to gauge the effective scale of holdings in Satoshi wallets.

The key is that coins remaining in existing address formats that are vulnerable to quantum computers would need to be moved to a new address format. Back argued users are likely to be given enough time to migrate, and that coins not moved even after that process could effectively be considered lost. "A transition to a post-quantum address format can tell us how much Satoshi still holds those coins," he said.

In the market, long-mined bitcoin, particularly holdings linked to Satoshi, has long been cited as one of the key variables in the quantum-computer threat. Estimates of Satoshi's holdings range from 500,000 to 1 million BTC, while on-chain analytics firm Arkham estimates 1.09 million BTC is held in wallets linked to Nakamoto. At current values, that is worth $81.6 billion, or about 1.21 trillion won.

Back, however, did not see the actual threat as imminent. "Quantum computing still has a lot to prove," he said, describing the current system as effectively at the laboratory stage. He also said a quantum-computing breakthrough capable of threatening Bitcoin signatures is at least 20 years away. Earlier this month, he also said, "The performance of current quantum computers is lower than that of a $5 calculator."

Still, Back's view is that preparations should begin now. The direction he presented was not to change the entire network immediately, but to keep the option open to switch when needed. "The safest approach is to build an optional upgrade that allows a move to quantum-resistant cryptography if necessary," Back said. The aim is to set out a response path while minimising the impact on existing users until the quantum threat reaches a real level.

Blockstream is already conducting related research. The company has worked on implementing hash-based signatures on Liquid Network, a Bitcoin layer-2 network, and Back explained that the Bitcoin Taproot protocol can also support alternative signature systems without affecting existing users. Blockstream Research in December 2025 proposed a hash-based signature system as a quantum-safe signature method to replace the Elliptic Curve Digital Signature Algorithm (ECDSA) and Schnorr signatures.

The discussion is also spreading to proposals for responses at the Bitcoin protocol level. Jameson Lopp and five co-authors on Tuesday released a Bitcoin Improvement Proposal that would restrict future movement of coins tied to address formats vulnerable to quantum attacks. It includes old coins whose public keys have already been exposed. The aim is to prevent a situation in which vulnerable assets are stolen en masse once quantum computers reach a practically usable level.

But that approach has also triggered backlash within the community. Developer and researcher Mark Erhardt criticised it as authoritarian and confiscatory. Phil Geiger, head of business development at Metaplanet, also pointed out, "It would mean that to keep the money from being stolen, we would first have to steal it." That implies that freezing vulnerable assets in advance could spark controversy over infringement of property rights, separate from the stated goal of stronger security.

As a result, debate over how the Bitcoin camp should respond is splitting into two tracks. One approach is to prepare in advance a path to quantum-resistant cryptography without undermining continuity of the existing network. The other is to block damage by pre-emptively locking assets exposed to quantum attacks. Back said that even if the quantum threat arrives faster than expected, developers will act quickly.

In the end, there are two points to watch going forward. The first is how far the Bitcoin community can agree on principles for handling quantum-vulnerable addresses. Alongside that, if actual transition procedures are introduced, the market is expected to focus on whether early holdings, including Satoshi-linked wallets, move to new addresses.