What did Adam Back say about Bitcoin and quantum computing?

Adam Back said a future post-quantum upgrade to Bitcoin could reveal how much of Satoshi Nakamoto’s Bitcoin is still accessible. He explained that users would need to move coins to new quantum-resistant addresses. Any coins left unmoved could be considered lost.

How could a quantum upgrade reveal Satoshi’s Bitcoin holdings?

During a migration to quantum-safe addresses, active holders would move their funds to protect them. Coins that remain untouched after the transition would likely be inaccessible. This process could reveal which of Satoshi’s coins are still controlled.

How much Bitcoin does Satoshi Nakamoto reportedly hold?

Estimates suggest Satoshi holds between 500,000 and 1 million BTC. Some blockchain data indicates up to 1.09 million BTC may be linked to Satoshi’s wallets. The exact amount remains uncertain.

What happens to Bitcoin that isn’t moved during a quantum transition?

Coins that are not moved to quantum-resistant addresses could be treated as lost. This means they may never be recovered or used again. This would reduce the effective circulating supply of Bitcoin.

How serious is the quantum computing threat to Bitcoin?

Adam Back said the threat is still likely at least 20 years away. Current quantum computers are not powerful enough to break Bitcoin’s cryptography. This gives developers time to prepare solutions.

What is a post-quantum Bitcoin upgrade?

A post-quantum upgrade involves changing Bitcoin’s cryptographic system to resist quantum attacks. This includes moving to new address formats and signature schemes. The goal is to protect funds from future technological risks.

What solutions are being proposed to protect Bitcoin?

Researchers, including Blockstream, are exploring hash-based signature schemes. These rely on cryptographic assumptions that are resistant to quantum attacks. Such upgrades could replace current systems like ECDSA and Schnorr.

Why are older Bitcoin wallets more at risk?

Older wallets may use cryptographic methods that are more vulnerable to quantum attacks. If their public keys are exposed, they could be targeted first. This makes early Bitcoin holdings particularly sensitive.

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Adam Back flags Satoshi stash quantum risk

Written by Brie CarterPublished Apr 17, 2026, 12:00 AMLast Updated Apr 24, 2026, 2:37 PM

Blockstream CEO Adam Back said a future post-quantum upgrade to Bitcoin could reveal how much of Satoshi Nakamoto’s estimated holdings remain accessible.

Speaking at Paris Blockchain Week, Back said users would need to migrate funds to quantum-resistant addresses, with unmoved coins likely considered lost after the transition.

“This migration to post-quantum address format may tell us how many of those coins (Satoshi) still has,”

Back said.

Estimates suggest Satoshi holds between 500,000 and 1 million BTC, though blockchain data indicates as much as 1.09 million Bitcoin could be linked to the creator’s wallets.

Back said the quantum threat remains distant, arguing that a breakthrough capable of compromising Bitcoin’s cryptography is likely at least 20 years away, giving developers time to prepare. Following the announcement the Bitcoin price was unchanged at $XX.

The discussion comes as developers explore proposals to restrict movement of vulnerable coins and transition to quantum-resistant systems.

Research from Blockstream has proposed hash-based signature schemes as a potential solution to secure the network in a post-quantum environment.

At the time of reporting, Bitcoin price was $74,661.74.