- IBM and IonQ quantum plans trigger urgent reassessment of Bitcoin’s long-term cryptographic integrity and defensive upgrade needs.
- Experts debate quantum thresholds, with estimates ranging from 2,500 to 3 million logical qubits to crack Bitcoin encryption.
IonQ and IBM have announced new targets for quantum computing, setting timelines that extend through the end of the decade. IonQ aims to build a machine with 2 million physical qubits and 80,000 logical qubits by 2030. IBM, meanwhile, plans to develop a large-scale, fault-tolerant quantum computer with 200 logical qubits by 2029. Later, it intends to release the Quantum Blue Jay system, which could reach 2,000 logical qubits and perform a billion operations.
These announcements, though primarily intended to support medicine, finance, security, and other scientific fields, have renewed concerns in the Bitcoin space. The question is direct: could these machines eventually compromise the cryptographic structure that secures Bitcoin?
Current Estimates on Quantum Threats to Bitcoin
Estimates vary widely. A user known as borovik argued last year that cracking Bitcoin would require between 13 million and 1.9 billion physical qubits. Other sources like Blockstream co-founder Adam Back set the figure closer to 317 million or 300 million, respectively. A team from the University of Sussex, however, believes it could take as few as 13 million qubits.
The key technical point lies in the distinction between physical and logical qubits. To function effectively, quantum computers must convert unstable physical qubits into stable logical ones. The conversion rate depends on the technology and error correction efficiency, but usually ranges from 100 to 1,000 physical qubits per logical qubit.
This means 13 million physical qubits might equal roughly 130,000 logical ones at best. Back’s 300 million would translate to about 3 million logical qubits. In contrast, IBM’s goal of 200 logical qubits and IonQ’s 80,000 fall far short of these levels. Based on those estimates, Bitcoin’s network would remain secure—at least for now.
Alternative Views and a Tighter Timeline
Not everyone agrees. Charles Edwards, founder of the investment firm Capriole, believes only 2,500 logical qubits would be enough to break Bitcoin’s encryption algorithm. He adds that quantum error correction is improving rapidly and forecasts a 50% risk within five to ten years. Quantum physicist Anastasia Marchenkova shares a similar view, stating that 2,500 logical qubits could compromise the network.
The Role of Cryptography and Quantum Capabilities
Bitcoin relies on ECDSA, a form of elliptic curve cryptography. This system secures private keys and, by extension, the control of funds. Traditional computers would need billions of years to break it. Quantum computers, by solving specific mathematical problems faster, could eventually undermine it.
However, this remains theoretical. No known quantum computer currently has the capacity to break Bitcoin’s encryption. And while progress in the field is steady, it’s not yet exponential.
Bitcoin developers have not remained passive
In April 2025, a Chilean developer proposed a hard fork to adopt quantum-resistant address formats. This measure would replace ECDSA with post-quantum cryptographic systems.
Ben Sigman, CEO of Bitcoin Libre, supported the idea, stating that the BIP-360 upgrade could improve Bitcoin’s defenses. Though this proposal is still under discussion, it signals that the network is considering real steps toward mitigation.
