IBM’s 120-Qubit Quantum Breakthrough Sparks Bitcoin Security Concerns

IBM’s latest quantum computing milestone has intensified fears in the crypto community about the potential vulnerability of Bitcoin’s encryption. In a groundbreaking study titled “Big Cats: Entanglement in 120 Qubits and Beyond,” IBM researchers announced the successful creation of a 120-qubit entangled quantum state—the largest and most stable of its kind ever achieved. This experiment marks a significant step toward fault-tolerant quantum computers capable of executing algorithms powerful enough to compromise modern cryptography, including Bitcoin’s encryption.

The team leveraged superconducting circuits and advanced compiler technology to minimize noise and maintain qubit stability. By employing techniques from graph theory, stabilizer groups, and temporary uncomputation, they achieved genuine multipartite entanglement across all qubits. The result reached a fidelity score of 0.56—surpassing the 0.5 threshold that confirms true quantum entanglement—demonstrating that all 120 qubits functioned as one coherent system.

IBM’s accomplishment outpaces Google Quantum AI’s 105-qubit “Willow” chip, which recently demonstrated quantum advantage by outperforming classical computers in physics simulations. The race among tech giants like IBM, Google, and Quantinuum highlights the rapid acceleration toward practical quantum computing—technology that could one day render traditional encryption obsolete.

Although today’s quantum systems remain far from breaking Bitcoin’s cryptography, experts warn that the danger is approaching. According to Project 11, around 6.6 million BTC—valued at more than $767 billion—could be at risk once fault-tolerant quantum systems emerge. These include Satoshi Nakamoto’s dormant coins, which are currently inaccessible but potentially vulnerable in a post-quantum era.

With IBM targeting fully fault-tolerant quantum computers by 2030, the countdown has begun for blockchain networks to transition toward quantum-resistant security measures. The quantum era is coming—and with it, a new challenge for the future of cryptocurrency security.