Bitcoin was designed so that only private key holders can access funds secured by that key. But could this security be compromised?
Josh Mandell, a former Wall Street trader, claimed on a now-removed social media post that quantum computers are being used to siphon Bitcoin (BTC) from old, inactive wallets, particularly those of owners believed to be inactive or deceased.
Mandell alleges a major actor is extracting Bitcoin directly from these wallets without impacting the market, leaving blockchain analysts as the only possible detectors of such activity.
If true, this would challenge the core principles of Bitcoin’s cryptographic security and ownership. However, is there concrete onchain data or technological capabilities to support this claim? This article examines Mandell’s assertions, expert feedback, and the current state of quantum computing.
Important fact: It is estimated that between 2.3 million and 3.7 million BTC are lost permanently due to forgotten private keys or dormant wallets.
Josh Mandell’s Allegations
Mandell insists that old, inactive Bitcoin wallets are quietly being drained using quantum computing technology. He suggests a significant player is accumulating BTC by cracking private keys of wallets whose owners are unlikely to notice.
- Targeted wallets: Long-dormant accounts assumed abandoned or linked to deceased owners.
- Off-market accumulation: Bitcoins taken without causing market disturbances or large sell orders.
- Detection difficulty: Only blockchain forensic analysis could highlight suspicious patterns, with no clear evidence currently available.
- Quantum advantage: Suggests quantum computers can break Bitcoin’s cryptography in ways classical computers cannot.
While presenting these points, Mandell offers no concrete proof, framing his claim as a technical possibility that may or may not be ongoing.
Did you know? Researchers at Oxford have achieved an error rate of only 0.000015% (1 error in 6.7 million quantum operations), setting a new benchmark in quantum computing accuracy.
Can Current Quantum Tech Breach Bitcoin Security?
Mandell’s claim focuses on quantum computers’ ability to compromise Bitcoin’s public-key cryptography. Let’s explore the complexity and reality behind this claim.
Bitcoin employs the Elliptic Curve Digital Signature Algorithm (ECDSA), especially using the secp256k1 curve.
Every Bitcoin transaction exposes the public key onchain. If an adversary could compute the corresponding private key from this public key, they could access any remaining bitcoins.
Shor’s algorithm allows quantum computers to theoretically break such cryptographic systems exponentially faster than classical ones, but only with quantum hardware significantly more advanced than what’s currently available.
Major technical barriers include:
- Logical qubit requirements: Physical qubits are unstable; fault-tolerant logical qubits demand heavy error correction, greatly increasing hardware needs.
- Qubit scale: Hundreds of thousands to millions of physical qubits may be necessary to break one Bitcoin private key, accounting for error correction.
- Operation fidelity: Quantum gates must be nearly error-free, a threshold current machines like Google’s 105-qubit Willow chip are just beginning to approach.
- Expert timelines: Many quantum researchers project practical ECDSA-breaking machines at least a decade away without major technological breakthroughs.
Mandell implies these hurdles have been overcome privately, enabling quiet key cracking of dormant Bitcoin wallets. However, publicly known quantum tech is nowhere near this capability.
Interesting fact: A single Bitcoin wallet linked to the Mt. Gox hack remains inactive today and holds nearly 79,957 BTC—about 0.4% of all Bitcoin.
Community Pushback and Expert Opinions
The Bitcoin and broader crypto communities have responded to Mandell’s claims with skepticism.
Harry Beckwith, founder of Hot Pixel Group, flatly stated there is no chance this is currently happening. Matthew Pines from the Bitcoin Policy Institute called the theory false and criticized the lack of evidence.
Their main points are:
- Quantum tech not yet capable: Present quantum machines lack sufficient qubits, error correction, and processing power for real cryptographic attacks on Bitcoin.
- Lack of clear evidence: While movement of old coins is observed, no patterns indicate theft via quantum computing, rather these are explained by wallet reactivations or inheritance-related transfers.
- Public keys exposure limitations: Quantum attacks require exposed public keys, often only momentarily, and many inactive wallets never reveal their public keys.
- Blockchain transparency: Dormant wallets are closely monitored. Any large stealthy theft would trigger alerts, which have not been observed so far.
Overall, the community agrees quantum risks are real but remain a future challenge, not an immediate threat as suggested by Mandell.
What Does Onchain Data Indicate?
True quantum-based theft would leave detectable traces on the blockchain. So far, such indicators haven’t been found.
- Dormant wallet activity: Several long-unmoved wallets from Bitcoin’s early years have moved coins, often interpreted as normal upgrades to wallet formats such as SegWit instead of unauthorized access.
- No unusual transaction signatures: No known patterns imply quantum key attacks, such as coordinated fund drains closely following public key exposure.
- No verified quantum theft: Beyond legitimate activity, no confirmed cases link coin loss directly to quantum computing.
- Legacy vulnerabilities remain: Some BTC still resides in older address types (P2PK, P2PKH) that expose public keys, representing theoretical quantum risk, but with no evidence of exploitation so far.
In essence, while cryptographic vulnerabilities may exist, current blockchain data provides no indication of active quantum-powered thefts.
Putting Mandell’s Claim in Context
Mandell’s alert about quantum computers stealing from dormant Bitcoin wallets remains unconfirmed.
Bitcoin’s ECDSA cryptography is still widely considered secure, with many experts anticipating at least a decade before quantum hardware could be threatening.
Some projections anticipate quantum risk emerging in the late 2020s particularly for wallets that have exposed their public keys. Currently, blockchain activity likely reflects benign reasons like wallet migrations, consolidations, or owner reactivations.
Key signs to monitor include sudden large movements from legacy formats, swift transfers following public key exposure, or demonstrable private key thefts.
Until such evidence surfaces, quantum threats should be regarded as future challenges to prepare for—not current realities.
