TL;DR
- Adam Back estimates Bitcoin has decades before quantum computing becomes a real risk.
- The Bitcoin network could implement post-quantum encryption standards (NIST) long before the danger arrives.
- The warning contrasts with Chamath Palihapitiya’s prediction, who sees the risk in just 2-5 years.
Currently, one of the most technical and divisive debates in the crypto ecosystem is the threat of quantum computing to Bitcoin. Some investors foresee a cryptographic apocalypse in the short term, while other players call for calm and perspective.
For example, the renowned cryptographer Adam Back, cited in the original Bitcoin white paper and current CEO of Blockstream, minimizes the risk. He recently used his X account to assure that the network has plenty of time to adapt. Back was clear: the danger probably won’t materialize “for 20 or 40 years.”
His statements were a response to a video by entrepreneur and venture capitalist Chamath Palihapitiya, who predicted the risk would become a reality in just two to five years.
One of the most authoritative voices in the industry explained that post-quantum encryption standards approved by the National Institute of Standards and Technology (NIST) already exist and Bitcoin could implement them “long before cryptographically relevant quantum computers arrive.”
The abyss between logical and physical qubits
The focus of the debate is the ability of quantum computers to break Bitcoin’s SHA-256 encryption standard. Palihapitiya suggests that about 8,000 qubits would be needed to achieve this. However, the current technological reality is much more complex.
Experts on the subject differentiate between physical qubits (unstable and prone to “noise”) and logical qubits (stable and corrected, the ones that really matter for cryptography). Although systems with more than 6,000 physical qubits (Caltech) already exist, they are incapable of breaking current encryption standards. For example, Quantinuum’s Helios system needs 98 physical qubits to produce only 48 logical ones. The industry is far from the thousands of stable logical qubits needed.
Although the quantum computing threat to Bitcoin seems distant, experts do warn of a current danger: “Harvest now, decrypt later.” Attackers could be storing encrypted data today, waiting for future technology to allow them to break it. This risk does not directly affect Bitcoin, which can be updated, but it does affect the long-term privacy of sensitive data.
Interestingly, Back suggested in April that if the quantum threat accelerates, it could reveal whether Satoshi Nakamoto is still alive, as the creator of Bitcoin would be forced to move his coins to a quantum-resistant address to protect them.
