Bitcoin Developer Adam Back Dismisses 'Quantum Hack' Claim as Misleading

• Adam Back has strongly pushed back against the claim, saying it’s wrong and misleading.
• A researcher reportedly demonstrated that a quantum computer could crack a 15-bit ECC key.
• BTC uses 256‑bit encryption, which is hugely different and about 2²⁴¹ times more complex.

News of the first quantum hack in crypto has rattled the industry, but prominent Bitcoin voice Adam Back has strongly pushed back, calling it wrong and misleading.

It all started when a researcher reportedly demonstrated that a quantum computer could crack a 15-bit ECC crypto key, leading some to speculate that Bitcoin’s security might already be at risk.

The development comes from a contest called the “Q‑Day Prize,” in which researchers try to crack elliptic curve cryptography (ECC) using quantum machines. It was reported that a 15‑bit ECC key was cracked, apparently using quantum hardware, and the researcher got paid 1 BTC for pulling it off.

However, Bitcoin uses 256‑bit encryption, not 15‑bit, which is a massive difference, and about 2²⁴¹ times (a number so large it has over 70 zeros) more complex. Additionally, Back dismissed the claims outright due to the fact that the method used was not even a true quantum cryptographic breakthrough.

It was said that the same results could be pulled off with classical (non-quantum) computers.

The original post reporting the “quantum hack” also got a community note on X stating: “The method used to recover the 15-bit ECC key relies on classical verification of outputs indistinguishable from random noise, equivalent to classical guessing.”

Although this particular claim has been exaggerated, experts agree that quantum computing remains a genuine long‑term concern for cryptography.

In the future, quantum computers could crack ECC, expose private keys from public addresses, and hit Bitcoin, Ethereum, and most of today’s encryption.

Some, such as QCP Group, have stated that quantum isn’t just a crypto problem and that it could impact the whole internet, even banking systems.

However, today’s quantum computers are far too weak to break 256-bit encryption. Experts note the serious risk is still years, if not decades, down the road.

For instance, Bernstein analysts said the quantum threat is real but manageable in the foreseeable future. Adam Back himself stated that the quantum threat is not immediate.

That being said, recently, several Bitcoin developers have proposed the BIP-361 (Bitcoin Improvement Proposal) to protect against future quantum threats. The plan is to freeze about 34% of all Bitcoin to stop potential theft by future quantum computers.

Related: Coinbase Raises Alarm Over Quantum Risk to Bitcoin and Crypto Wallets