Quantum Computer: The biggest existing threat to Bitcoin

Quantum computers are no longer a science fiction story or an obsession of the cypherpunk community. They have become a real threat, making headlines — especially with the first non-national currency of humanity. If you ever thought that Satoshi's creation was immune to existential risks, you should think again. The latest report from the Human Rights Foundation ( – HRF) has sounded the alarm.

Quantum threats to the security foundation of Bitcoin

The HRF report emphasizes that Bitcoin is not just a speculative tool, but also a “lifeline” for activists, journalists, and dissenters facing financial repression. The decentralization, privacy, and permissionless access of Bitcoin have helped them maintain their funding and protect their assets from confiscation.

However, all of this is based on a solid cryptographic foundation — and quantum computers are the only technology capable of breaking through that invisible protective layer. According to HRF, approximately 700 billion USD worth of Bitcoin is at risk. About 4.49 million BTC can still be protected if owners quickly transfer to quantum-resistant addresses.

The slow development speed of Bitcoin makes it difficult to implement security upgrades. The community is fiercely debating whether to “burn” the coins that cannot be moved — even though this action goes against the neutrality of the network — or to accept the risk of letting “quantum hackers” steal them.

Additionally, “quantum-resistant” transactions will cause the blockchain to swell, exacerbating the scalability issue that Bitcoin has struggled with for many years. As Coin Metrics co-founder, Nic Carter, candidly stated:

“Quantum Computer, in my opinion, is the biggest threat to Bitcoin. It is a serious issue for many other financial systems, but for Bitcoin, this is a particularly large and difficult challenge to solve.”

6.5 million Bitcoin are facing risks

HRF's report estimates that about 6.5 million BTC — almost 1/3 of the total supply — are vulnerable to “long-range quantum attacks,” targeting old or reused addresses. Of those, approximately 4.49 million BTC could be protected if users timely move to new addresses.

The remaining part — about 1.7 million BTC, including 1.1 million BTC believed to belong to Satoshi — is almost “inactive” and may become the first target when a Quantum Computer is strong enough.

There are two main types of attacks:

• Long-range attack (: targeting old addresses, exploiting leaked public keys.
• Short-range attack )short-range(: stealing coins during the transaction confirmation wait time by calculating the private key in real-time.

“Burn or be burned”: the political dilemma of the protocol

The decentralized upgrade mechanism — which is the greatest strength of Bitcoin — becomes a weakness in this situation. Unlike operating systems that can update automatically, Bitcoin requires global consensus, which often takes many years.

The debate over whether to burn, freeze, or abandon easily attackable coins is becoming increasingly heated. Every option touches on the core values of Bitcoin: ownership rights, anti-censorship, and resistance to government. HRF asserts:

“Upgrading Bitcoin to defend against the quantum threat is not only a technical challenge but also a test of human will. Success requires cooperation among users, developers, hardware manufacturers, node operators, and civil society organizations.”

New algorithm, larger blocks, and a new headache

Quantum-resistant solutions are categorized by HRF into two main groups: lattice-based signatures and hash-based signatures. However, both expand the size of transactions:

• The lattice-based signature is 10 times larger than the current one.
• The smallest hash-based signature is also 38 times larger.

This means fewer transactions per block, heavier network nodes, wallets needing redesign, hardware needing upgrades, and global users needing retraining.

With the slow pace of upgrades in the past, coupled with the fact that no one knows when quantum computers will reach a dangerous threshold, the window for action may close faster than expected.

The Future: Resilience or Collapse?

Sustainable solutions can only come from the unity of the community, not just from a few lines of code on GitHub. The fate of millions of forgotten Bitcoins — and perhaps the reputation of the entire ecosystem — will depend on how the network addresses these technical, political, and social conflicts in the coming decade.

For those who believe in financial freedom and the cypherpunk philosophy, the message is very clear: Keep learning, upgrading, and never assume that Satoshi's armor is invulnerable.

Bitcoin security expert Jameson Lopp once warned:

“The biggest threat to Bitcoin is not just Quantum Computers, but indifference. When the community stops discussing ways to improve Bitcoin, that is when the network becomes the weakest and most vulnerable.”